1. Field of the Invention
The present invention relates to the art of vehicle suspension, and more particularly, to a device for controlling the damping coefficients of shock absorbers provided between a body of a four wheeled vehicle and the wheels thereof by constructing a phantom damping system substantially equivalent to the damping system provided by the actual shock absorbers.
2. Description of the Prior Art
In the art of the vehicle suspension, it is already known to variably control the damping coefficients of the shock absorbers incorporated therein so that a more desirable suspension performance is available.
For example, when the damping coefficient of a shock absorber disposed in parallel with a suspension spring supporting the vehicle body at a corresponding portion thereof on a wheel is variably controlled to be proportional to a ratio of the vertically stroking velocity of the corresponding body portion to the difference between the vertically stroking velocity of the corresponding body portion and the vertically stroking velocity of the wheel, the shock absorber can be imagined as acting between the vehicle body and a phantom stationary overhead construction, as generally called "sky hook damper.
If the shock absorber for the vehicle body could act against a stationary overhead construction, the stability performance of the vehicle body would of course be much improved, because the end of the shock absorber opposite to the vehicle body would no longer fluctuate as it actually does together with the wheel along the road surface in the actual construction.
On the other hand, when the four wheeled vehicles turn, the vehicles would become more stable against a rolling due to the turn if the center of gravity of the vehicle body is lowered. In view of this, in a co-pending earlier patent application No. (1243), a basic inventive concept of which is originated in the inventor of the present application, it has been proposed to control the damping coefficient of shock absorbers mounted in an ordinary arrangement between each wheel and a corresponding portion of the vehicle body of a four-wheeled vehicle by constructing a phantom damping system as a substitute for the actual shock absorbers, so that the vertical damping force against the vertical stroking and the angular damping moment against the rolling of the vehicle body are equivalently provided by a combination of a phantom side shock absorber located laterally inside of a turn of the vehicle as arranged to act vertically and a phantom angular shock absorber arranged to act between an upper end of the phantom side shock absorber and the vehicle body. By the damping coefficients of the actual shock absorbers being so equivalently controlled by way of the phantom damping system, when the vehicle body rolls, it rolls around a pivot point between the upper end of the phantom side shock absorber and the corresponding lateral end of the phantom angular shock absorber, so that the center of gravity of the vehicle body is lowered according to a rolling thereof due to a turn running of the vehicle.