Based on the theory of passive suspension feasibility design area and the engineering practice, this article takes a non-linear outer characteristic as the reference,which is structured by the suspension shock absorber s open-up damping coefficient, full-open damping coefficient and the smoothness-to-safety ratio.

This article is a bench test and road test study on a mini car front suspension shock absorber in the condition of the low temperature noise,which comes up in winter in the north-east area of China.

By setting up a concept of smoothness - to safety ratio in the suspension shock absorber outer characteristic, this article takes the Linear data of passive suspension feasible design area to present a feasible method in the nonlinerar desigm of suspension shock absorber outer characteristic.

The popular way of testing the performance of a shock absorber is on test-rig, which won t work out while the car is running.

In this paper,the Lagelangri equqtion is applied to deduce accurate movement derivative equation of mechanism of reducing vibration in centrifugal swing,and on the basis of structure of mechanism of reducing vibration in hanging swing for engineering practice,presents the revision of movement derivative equation to consider effect of parallel quadrilateral.