Product and Process Robustness Enhancement for a Top Class Automotive Gearshift Tower

Automotive engineering is a challenging task for modern engineers. Requirements and technical specifications are more and more demanding, especially in relation with high performance and luxury class. Such aspects involve both functional and emotional aspects and pursues total quality, equally in product and manufacturing process. Moreover, a structured concurrent and co-design based engineering approach, involving the whole value chain, is required while cost need to be reduced, time saved and human and industrial resources spared. The present paper deals with the design and manufacturing optimization of manual selection and clutch mechanism in a gearbox tower, realized to provide top class cars. Gearbox tower is the mechanical interface between drivers and engine transmission system in automotive applications. It has the primary function to permit driver selecting and shifting gears during vehicle march, to optimize engine running. Furthermore such mechanism has a central role in enhancing the overall market perception of the product and in transmitting to the customers good feelings about driving quality and car reliability, according to top class targets. Robust design approach was primary followed, focusing on the continuous improvement of products and processes [1], [2]. Different existing solution for gearbox tower were firstly analyzed, performing a concurrent engineering analysis of each mechanical component from functional, productive and assembly points of view. Technical and technological aspects were discussed and compared through FMEA (Failure Mode and Effects Analysis) while an integrated CAD/CAM analysis (Pro/ENGINEER Wildfire 2.0) were carried out to optimize 5-axes CNC manufacturing. SPC (Statistical Process Control) were concurrently performed to maximize efficiency and process consistency. A novel gearbox tower was finally designed. Three-dimensional parametric virtual prototype was realized and evaluated into its kinetic-dynamic characteristics within SolidWorks 2006 (Figure 1) and COSMOSMotion environments, in order to test the impact of different Computer Aided Tools inside a holonic and collaborative supply chain. The method developed and the following studies leaded to the general enhancing of the gearbox project, especially in its more critic aspects. The gearbox tower family was optimized in its technical aspects and engineering performances respect to the state of the art. Moreover it was improved in terms of total quality perception from final users. Results obtained leaded to the develop of specific solutions focused in make the product and the related process more robust in the overall life cycle.