Study on the Relationship Between Wheel Stiffness and Driving Stability – An Examination of Wheel Stiffness Optimization Using Tire Contact Patch Analysis

This paper relates the experimental analysis carried out to obtain a quantitative grasp of the influence of wheel stiffness on driving stability, which up to now had been inferred through a reliance on rule of thumb. For the disk section and the rim section, stiffness alternatives with additional wheel reinforcement were prepared, and comparative testing of the influence that wheel stiffness has on tire contact patch characteristics, tire lateral force, and driving stability was carried out by bench and driving tests. Wheel stiffness was divided into the disk section, the rim section, and the hub fixing section for evaluation. Disk reinforcement has an influence that reduces change in the camber angle of the disk. Rim reinforcement has an influence that reduces the displacement to the ground of the rim. The disk stiffness and rim stiffness have different respective influences on tire contact patch characteristics. Disk stiffness is related to tire contact patch length, and rim stiffness is related to tire contact patch area. Tire contact patch length is related to the maneuverability of driving stability. Tire contact patch area of the tire is related to the stability of driving stability. The balance between maneuverability and stability was successfully enhanced by optimizing the proportion between disk stiffness and rim stiffness. In addition, the amount of additional wheel reinforcement necessary to achieve the objective of enhanced balance between maneuverability and stability was successfully minimized. The substance of the report follows.