1, the concept
unsprung mass, is a word came into English, English: Unsprung Weight. It refers to a non supported by the vehicle suspension system weight: tires, wheels, brakes. Appropriate, Sprung Weight refers to a suspension system to support the weight of the car, it is the quality of the vast majority of cars.
and to recognize and distinguish between the two, for the stability and handling of a car of great significance. Printing of rumors: 1KG reduce the unsprung mass may be equivalent to reduce the effectiveness of the sprung mass of 15KG. Of course, then the data is not necessarily accurate, but the effect and the impact it is. In the case of the sprung mass unchanged, reducing the unsprung mass can enhance the car’s acceleration, handling and stability to some extent.
2. Principle
As we all know, a car accelerates from rest to start the process requires a lot of energy. And let the tires do not move from place to scroll up also requires a lot of energy, the heavier the tire, the greater the energy required. Thus, the weight of the tire (or wheel) is reduced, thus reducing the required power, it can enhance acceleration. When
On the other hand, the tire (or wheel) to reduce the weight, inertia also becomes small, uneven surfaces encountered potholes on the fast reaction of the corresponding (not discussed suspended, of course, influence is great), stability and handling will naturally rise.
binding sprung mass, such a simple formula: (sprung weight) / (unsprung weight) = substantially the better.
Since the ground pressure of the tire is provided by the weight of the vehicle, if the vehicle is heavy, naturally the tire ground contact pressure increases, but when pressed against the rough road, the quality of the tire on the hanger the up and down movement speed has a great influence, the greater the unsprung mass, you need to do to change the direction of movement of the longer (with fixed suspension is set) will result in reduced road rolling tracking performance, if the car weightA small amount, the suspension can not be effectively fixed to the fulcrum of the effective relative position, so that, when the tire is also no chance to move to the appropriate degree of change in the ground undulations, the vehicle body to float.
3. Application
Therefore, in certain unsprung mass, we need to reduce the unsprung mass as possible. From a structural point of view, independent suspension unsprung mass than the light non-independent suspension, so it is better handling stability, and lightweight aluminum alloy wheels, and a suspension element (tie rod, rocker arm, etc.) The reason is widely used, mainly because they can effectively reduce the unsprung mass.