Steed Webzell reveals the high levels of innovation being applied to welding processes in automotive manufacturing
Welding remains the dominant joining technology for the automotive manufacturing sector but developments in technology, equipment, quality control and automation are crucial to evolving more efficient processes to produce ever lighter and stronger compOnents and vehicles.
Manufacturing technologies have a huge role to play in ensuring reliability - from the power source and controller through to the robot manipulator, consumables and monitoring equipment. In combination with modern manufacturing trends such as supplier consolidation, equipment standardisation, error-proofing and preventative maintenance, the ultimate goal is unmanned running with zero rejects.
An increasing number of plants are integrating smarter sensors, vision systems, in-line bypass measurement and welding quality management systems in search of better quality control – pairing such technologies with automation to achieve best practice welding.
New laser welding applications in powertrain production are tackling difficult to weld materials such as grey cast iron, while weight reduction is also of huge influence, with laser welding of differential components, for example, eliminating the need for previously threaded connections. As a result, parts are shorter and lighter.
The trend is even more marked in the body shop where widespread use of laser welded tailored blanks allows for the production of lighter body-in-white structures.
Materials are the driving force in many new welding innovations, for obvious reasons. For instance, several new possibilities resulted from the advent of laser plastics welding, while induction welding for composites will surely be commonplace in years to come. Similarly, the age-old aluminium-to-aluminium welding dilemma finally appears to be reaching a level of resolution.
One recent example of welding innovation helping a major OEM make genuine advancesis at Honda. Despite limited success in spot welding steel and aluminium, the production of reliable welds proved inconsistent. However, in its 2013 Accord model Honda has used a variation on friction stir welding in which metals are joined via mechanical pressure. The technology generates a new and stable metallic bond between steel and aluminium by moving a rotating tool on the top of the aluminium which is lapped over the steel with high pressure. The welds are reportedly equal to or exceed the strength of those made by regular MIG welding. Furthermore, steel/aluminium sub-frames built with the new technique are said to be 25% lighter than those entirely in steel.
The process also makes it possible to alter the structure of the sub-frame, so that the mounting point for the suspension can be relocated – reportedly increasing the rigidity of the mounting point by 20%, improving the car’s dynamic performance.
Additionally, the new process uses about half the amount of electricity as MIG welding through smaller machines actually attached to industrial robots.
Read on for many more examples of how innovation can impact auto plant manufacturing operations.