Systematic Approach for Static Steering Effort Reduction through Linkages Optimization in Small Commercial Vehicles (SCV)

The steering system design of a vehicle is of utmost importance as it not only acts as an interface between the driver and the entire vehicle but also is one of the key vehicle sub systems, which accounts for vehicle overall performance including vehicle handling and stability. With recent infrastructure development and changes witnessed in doing commercial vehicle business to hub and spoke and to door to door logistics delivery are expecting improved vehicle performance. More particularly in small and light commercial vehicle segments (SCV and LCV) where the business demands are more for the movement of vehicle in narrow city lanes and sharp corners. Also, now driver comfort is considered one of the key factors before purchasing any commercial vehicle. Thus, having power steering in SCV’s and LCV’s has not only become a mandate but also the vehicle steering system performance should be such that the driver can easily maneuver the vehicle in narrow city lanes and corners. Through this paper a methodology has been devised in which factors contributing to achieving static lock to lock maneuverability in a power steering vehicle have been analyzed without overdesigning the hydraulic power assistance of the vehicle. The approach mainly focuses on LH/RH symmetric hydraulic pressure build up in the system by critically designing the steering system linkages hard points such as drop arm length, drop arm SAP angle, steer arm length, track rod arm’s length. Also, this study also ensures that the derived hard points not only enhance hydraulic assistance in the steering system but also ensures the vehicle to have least turning circle diameter (TCD) and enhanced tire life by having least Ackermann error.