Success Story: Volkswagen AG Preproduction Quality Assurance
28.05.14 - Volkswagen AG in Wolfsburg’s Preproduction Quality Assurance Relies on Measuring Solutions from WENZEL.
In order to continuously improve quality, productivity and process efficiency, it must be ensured that every Volkswagen Group automobile is ready to be measured at an early stage of development. This applies to all brands and variants, from the roof to the floor assembly. With the RAX horizontal arm measuring machines from WENZEL, Volkswagen has created the ideal solution. There are now five duplex systems in use.
Quality assurance in the preproduction center at Wolfsburg practiced excellence in metrology. On test vehicles new trends are set in metrology. Developers are confronted here first with new measurement tasks. The controllability of these measurement tasks has an effect on the whole product development process.
"In product development, we must define as soon as possible, which requirements and quality criteria need to be considered," explains Stefan Eckhardt, Department QA Pre-Production and Analysis Center. His supervisor Frank Eggeling adds: "We cover the full range at Volkswagen. Therefore, a large measuring range for us was very important so that, for example, a VW bus can be measured with high accuracy."
Recipe for Success
Close Cooperation "Before the introduction of our measurement solution measurement was undertaken using relatively large coordinate measuring machines, of course" says Thomas Werner, Head of Technical Sales at WENZEL. "But the mechanics were getting on in years and the control technology, the software and the probes were technologically no longer up to date" Volkswagen options ranged from comprehensive modernization to a complete new acquisition. It was an important requirement that the new solution is future-proof, for at least 10 years.”
After an intensive in-house selection process, Volkswagen decided on a completely new development from WENZEL. The decision for the RAX horizontal arm measuring machine was a big vote of confidence in WENZEL’s innovative competence. The project was performed from start to finish in close cooperation with Volkswagen." The requirements were very high. But the cooperation with measuring technicians who have years of experience has been a great asset for us," said Werner.
Enormous Measuring Range
The result is the RAX, the latest CNC horizontal arm measuring machine from WENZEL’s proven R Series. The WENZEL-Team is proud that the RAX was more precise than required and more accurate than comparable smaller measuring machines, despite the high-Z range. The accuracy of the CMM is specified by the volumetric length measuring uncertainty MPEE from 40 + L/40 ?m. The coordinate measuring machine is suitable for touch trigger, scanning and optical probe systems.
The standard version of the RAX offers a large measuring range of 3100 mm in the Z-Axis. Due to the mirror-image structure of the duplex version the measuring range in the X-Axis will be utilized optimally. Depending on the probe system the measuring range starts 70 mm above the base plate in the Z-Axis. At Volkswagen, the X-axis is 6,000 mm. If necessary, much longer systems with multiple columns can be created.
Perfectly accessible for all measurement and maintenance tasks
The high-precision linear guideways in all axes meet the steadily increasing demands of precision measurement technology. The X-axis guideways are integrated at floor-level into the base plate. This design allows the RAX to be loaded with heavy components or complete vehicles. The drives have been optimized based on the well-tried WENZEL technology for the new construction. The measuring machine is perfectly accessible from all sides for measurement and maintenance tasks. All relevant components can be removed and re-installed with little handling. This reduces maintenance time and increases the availability of the coordinate measuring machines.
Special equipment for CMMs
The RAX systems are equipped with active temperature compensation. This ensures that accurate results can be determined despite possible different temperatures. The work piece temperature sensors are installed wirelessly. The existing foundations could still be used. These are equipped with dampers, so that the influence of vibration on the measurement result is minimized.
The measuring machines are monitored by light barriers so that the high machine speeds can be fully achieved. The mirror columns of the light barriers can be easily removed, when a vehicle has to be placed on the CMM. Thereafter, the column can be placed reproducibly without further adjustment. The measuring machines are equipped with the PHS servo positioning head from Renishaw, which is a 2-axis motorized head with continuous 360° servo drive enabling the probe configuration to be positioned at almost any angle. The PHS was designed to meet the demanding requirements for measurement of car bodies in the automotive industry where fine angular position and long reach are needed.
Wide range of applications
VW measures nearly everything out of the automotive sector with the RAX measurement systems, complete vehicles, bodies and body parts. In addition, the RAX can be used in many other industries for example for large-scale machine parts, trucks, agricultural and construction equipment, as well as parts for the aerospace and energy sectors.
"We have now been working for two years with the RAX CMM and we are very satisfied," explains Hans-Jürgen Bach, Head of QA Pre-Production at the Volkswagen AG in Wolfsburg. "It was important for us that we get the complete portfolio of services from a single source." Stefan Eckhardt, adds: "With the solution we are well positioned for the future. Through continuous development from WENZEL it is possible for us at any time to upgrade to the latest state of the art."
