Excellence of Laser Welding in Structure and Appearance Design

Laser welding has become a standard process in the automotive industry. In the context of automobile body assembly production lines, the utilization of five-axis laser processing machines or laser processing systems with optical fiber transmission has been extensively employed for the welding of car body components. The three major American automotive conglomerates (General Motors, Ford, and Chrysler) as well as European automobile manufacturing companies (such as RENAULT, VOLVO, AUDI, MERCEDES-BENZ, and BMW) have all adopted laser welding robots within their production lines. To illustrate with the case of General Motors, its utilization of laser systems online exceeds a count of 200 units. Germany’s Volkswagen Group has incorporated laser welding in the manufacturing of various branded vehicle models including Audi A6, Audi A4, Golf, and Passat, primarily for welding the car roofs.

1. Structure Design

In contrast to the traditional paradigm, laser welding demands a heightened level of stability in three-dimensional accuracy. This necessitates more stringent precision requirements and quality assurances in the design of body weld seam placements. To ensure the steadfastness of body production, it becomes imperative to exercise control over the functional dimensions of various components associated with laser brazing. Additionally, it is essential to establish that when fluctuations occur within an appropriate range, the visual quality of the welding remains unaffected.

The stamping components for the body side panels and roof adopt the conventional approach of multiple stamping steps. This method struggles to ensure the demanded tolerance range for the laser welding area. Thus, stamping processes must rigorously uphold geometric dimensions. Departing from the traditional dual-stage shaping approach, the strategy involves a singular-stroke stamping methodology for the A, B, and C regions. This transition entails a shift towards processing and installation carried out using the same manufacturing baseline, equipment, and installation fixtures. The aim is to ensure uniformity in the surface level of the laser welding area.

2. Appearance Design

The application of laser welding results in a more aesthetically pleasing body, where the welded joints are virtually devoid of visible traces, and post-polishing gives them a seamless appearance. For instance, the exterior of a laser-welded roof presents a uniform surface, whereas traditional spot welding methods often leave marks on the vehicle’s roof, necessitating the use of decorative strips on both sides for concealment. As a result, many individuals discern whether a vehicle employs spot-welded bodywork or laser-welded bodywork by observing the presence or absence of these decorative strips on the roof.

When designing the body roof, it’s crucial to adjust the angle of the roof’s contour based on requirements of calibration, specifically the angular orientation of the laser welding surface. This calibration ensures that the side panels and roof can be welded together within an ideal gap and angle.

With advanced manufacturing technologies, achieving automation, flexibility, and intelligence in the production of welded products has become an inevitable trend. In international aspect, well-known automotive companies are racing to implement laser welding technology in body manufacturing to ensure both product quality and technological advancement, securing a competitive edge in the increasingly fierce product market. This trend has also been reflected in domestic joint ventures. Elevating product quality, conducting pertinent research applications within China, gaining mastery over pivotal technologies and welding machines, and forging self-reliant capacities in research, innovation, and production, stand not only as prevailing trends but also as the bedrock for propelling Chinese brands onto the global stage.

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