The "Corolla Sport" hatchback, which Toyota Motor Corp released in June 2018, uses a newly-developed shock absorber (damper) of KYB Corp.
A damper prevents the vibration of a road surface from being transmitted to the auto body. By employing an idea of intentionally increasing the friction of a damper at the time of turning a vehicle, Toyota enhanced the turning performance of the vehicle.
In the development of a damper, the friction of its piston sliding surface is usually reduced, according to Toyota. And it is very rate to increase the friction intentionally because the larger friction deteriorates ride comfort.
This time, Toyota made improvements so that the friction increases only at the time of turning the vehicle, realizing both a high ride comfort and high turning performance.
A damper is one of the parts that connect the wheels and the auto body. It is a key component that prevents the vertical vibration of the road surface from being transmitted to the auto body and improves ride comfort and stability.
Oil and a piston are put in the cylinder of the damper to reduce damping force in accordance with the speed of the input from the road surface to the wheel. When friction increases, the piston cannot be easily moved, preventing damping force from being generated. The reduction of friction is the most important part of the development of a damper.
Nevertheless, Toyota and KYB employed the idea of increasing friction to decrease the speed of the rolling of the auto body (movement in the right-left direction when seen from the front side of the vehicle) at the time of slowing turning the vehicle to, for example, switch lanes.