To resolve the issue of the conflicting objectives of comfort and driving dynamics, Vibracoustic has developed switchable air springs with a three-chamber concept. By switching individual air chambers on and off by means of intelligent controls, the air springs can be set to four different stiffness levels depending on the particular driving situation. This makes driving more comfortable or dynamic, as well as safer.
In the case of electric vehicles air spring applications at the back or on all four corners of the vehicle are becoming increasingly popular. This allows the level of the car to be controlled, which is particularly important for pure electric vehicles as it allows airflow guidance beneath the car. This is especially important for efficient passive cooling of the battery packs, which are predominately positioned at the floor area of the car.
The concept of the three-chamber air spring system is easy: The greater the volume available, the softer the springs, and the lower the air volume, the stiffer the springs. In current Vibracoustic applications, the stiffness of the springs can be practically doubled, from very soft to extremely stiff, over four gradients.
The newly developed switch valves that control the flow rate also play an important role with regard to the new air springs. The switching times need to be short enough and the opening also needs to be adequately sized. However, the developers also minimized switching noise using a membrane, to ensure that it is not perceptible by drivers or passengers in the vehicle. This feature is particularly important for electric vehicles, where there is no noise or vibration from the combustion engine to cover this type of noise.
In the future, Vibracoustic will also provide switchable air springs in dual-chamber systems. While these systems can only offer two different stiffness levels, the corresponding regulation also enables effective roll stabilization. Vibracoustic thus also aims to meet customer demands for improved comfort and driving dynamics in mid-range vehicles.