INVESTIGATION OF ATTENUATION MECHANISM OF NON-LINEAR DAMPER FOR SUPPRESSION OF MICRO-VIBRATION ON A CAR BODY

摘要

The present damper developed for a micro vibration suppression of a car body, that uses an oil hydraulic pressure control valve for generating damping force, is able to produce a velocity-independent nearly constant damping force unlike an ordinary viscous damper and hence to produce a large damping force even in a very small velocity range. Previous report elucidated firstly the generation mechanism of damping force in quasi-static state and then derived the equation for attenuation characteristics, specifically derived the damping coefficient by linearizing the nonlinearity due to a built-in oil hydraulic pressure control valve by using describing function method. In this paper, firstly the attenuation model is enhanced in order to be able to estimate damping characteristics of the test damper more precisely even in dynamic state by introducing the time-delay elements into the previous model. Then the validity of modelling of damping mechanism is verified on the basis of comparison of simulations with experiments. Finally, it is concluded clearly that the present modified model can simulate the characteristics of damping force vs piston speed more precisely than original model.