A vibration transfer reduction technique, making use of the directivity of the force transmitted from road surface to tire: part 2: analyses on transient vibration of unsprung mass by means of force measurement on running vehicle

摘要

An empirical theory that a slight rearward inclination of suspension travel locus in side view gives a better harshness performance, has been studied through quantitative measurements of forces and motion of unsprung mass of vehicles duringdriving. It has been found that the force transmitted from road to tire has a directivity, which has been slightly inclined rearward, in the frequency range around 5 to 15 Hz. We have named the angle of it as "input inclination angle". In general, the transfercharacteristics of suspensions in the direction normal to suspension travel have a peak gain around 13Hz. Therefore, a suspension travel direction, which is inclined by the input inclination angle, gives minimized fore & aft force transmission at thefrequency range of unsprung mass resonance.The optimum inclination angle of a suspension travel locus was estimated to be 6 deg. rearward approximately, from harshness point of view.