Study on kingpin axis behavior of front suspension under the turning lateral force.

Abstract

In this paper, we considered how the kingpin axis transitions due to the turning lateral force acting on the front wheels of a turning vehicle. Two types of consideration were conducted: qualitative consideration and quantitative consideration using CAE. In the qualitative consideration, we discussed the transition of the kingpin axis due to the elastic characteristics of the suspension when there is no artificial steering, that is, when only the turning lateral force acts on the front wheels. As a result, it was clarified that the caster angle and the caster trail of the kingpin axis increased due to the elasticity of the suspension. Next, in the quantitative consideration, we discussed the transition of the kingpin axis when the steering angle and turning lateral force acting simultaneously on the front wheels and suspension, assuming a lane change at high speed. For the steering angle and turning lateral force, the values in an actual high-speed lane change were used. As a result, We clarified that the caster angle and the caster trail of the kingpin axis are decreased. And then the kingpin angle and the kingpin offset are increased during the initial steering of a high-speed lane change about the strut type front suspension, which is commonly used in front wheel drive vehicle with transverse engine.