Development and design of a driver’s chair : - The continued development of the 3B driver’s chair concept

Sammanfattning: The driver’s environment in todays trucks is being continually improved to increase the drivers comfort and safety. One of the most influencing factors of the driving experience is the driver’s chair. The purpose of this master thesis was to continue the development of a new driver’s chair, based on a pilot study and a number of patents from Scania CV AB. The aim of this development was to create one or several concept chairs, ready for further prototyping and analysis. The concept(s) were to be constructed using CAD software, thus verifying dimensions and functions. Beyond this, the concept(s) were to be calculated and simulated for structural integrity during a crash. A product development process divided into three phases, information gathering, concept development and construction, was used. During the first phase, information was collected with the purpose of increasing subject knowledge, identifying user demands and mapping out useable technologies. In the second phase, product development, a product specification was created and idea solutions were generated. Eight pilot concepts were created from the generated ideas. The concepts were transformed into CAD mock-ups, verifying movement patterns and secondary functions. Finally, the concepts were evaluated and selected with the aid of quantitative evaluation methods. The selected concept differed somewhat from the patents, but kept the same basic method of chair suspension. These differences were caused by forced adaptations of the concept structure to conform to product specifications. In the third phase, mechanical construction was performed in parallel with a master thesis aiming to simulate and verify crash testing of the concept. An iterative loop between construction and simulation was set up to quickly create a robust chair frame. With the frame properly designed and evaluated, the chair’s secondary functions could be designed and applied. The resulting concept was deemed to have the potential to conform to product demands, in some cases outperforming the current chair models. The biggest advantages of the concept were increased safety due to the sturdy frame, a suspension independent of chair settings and a potentially lower weight. One specific demand was that the concept must be able to fit in all of the cabs in Scanias cab range. Concessions and trade-offs in chair geometry and structure had to be made to meet this goal. This led to an increase in the complexity of the structure and the elimination of some of the patents inherent strengths, but secured cab compatibility and kept in important comfort functions. The conclusion was that the pilot study and the patents were considered possible to put into practice, but in a less effective and optimal way compared to what was originally thought to be possible. Removing or reducing the demand on cab compatibility, the concept was still deemed to be able to reach its full potential with additional development.