Automatic load-dependent brake

An automatic load-dependent brake is a vehicle braking system that uses a mechanical connection from the axle to the vehicle body / body to make the braking effect dependent on the load level. When the vehicle is heavily loaded, the braking effect is increased, and when the vehicle is lightly loaded, the brakes are reduced less in order to minimize the risk of the wheels locking . The system determines the load level through a direct connection to the suspension .

With conventional parabolic suspension, the distance between the vehicle body and the axle is measured, which becomes smaller as the load increases. For this purpose, a linkage is led from the axle carrier to a three-stage valve located on the vehicle frame.

With air suspension, which is very often used today, this distance is always the same, since the air suspension always raises the frame to the same level. The heavier the vehicle, the greater the air pressure in the bellows has to be. The air pressure in the bellows is transmitted via an air hose to a valve, which regulates the brake pressure steplessly depending on the bellows pressure.

In the meantime, there are also systems that recognize the load status via the slip of the tires when starting and thus regulate the braking effect of the axle . The higher the load, the higher the torsion of the profile blocks when starting. This slip is recognized by the ABS sensors. The load status is recognized via a map .

An automatic load-dependent brake is not to be confused with the anti-lock braking system , which also aims to prevent the wheels from locking, but using a different approach.

literature

• Karl-Heinz Dietsche, Thomas Jäger, Robert Bosch GmbH: Automotive pocket book. 25th edition, Friedr. Vieweg & Sohn Verlag, Wiesbaden, 2003, ISBN 3528238763