The Influence of Body Layout on Vehicle Pitching Behavior in ATV (part 1)

This paper intends to verify the following in order to clarify the influence of the body layout on ATV pitching behavior, and for the purpose of helping develop a more pleasing product, it reports the research results based on the theory and experiment concerning the effect of body geometry on vehicle dynamics, with particular emphasis on vehicle behaviors under acceleration and deceleration. A discussion of vehicles employing the chain drive or swing arm system involves a number of factors that contribute to pitching motion. Such factors can be roughly divided into two effects. One effect arises from a load transfer in every vehicle due to the inertial force acting on sprung mass, and the other is the force that is activated by a chain drive and a swing arm system and thus demands geometrical consideration. In an attempt to grasp an accurate pitching behavior in relation to the vehicle geometry during acceleration, we first made a theoretical inference about the behavior and then conducted a qualitative and quantitative evaluation of it on actual vehicles. In view of few changes in the line of action due to suspension geometry, we made a theoretical calculation using the value in the case of a 1G behavior for the sake of simplicity. As a result of comparison of this behavior with acceleration and deceleration behaviors on actual vehicles, we were able to find a good qualitative and quantitative conformity in the acceleration behavior. We were also able to find a qualitative conformity in the deceleration behavior.