Vehicle Acoustics Test Bench
Vehicle acoustics test benches are generally designed as roller test benches with anechoic lining on walls and ceiling. This construction has a major disadvantage: the noise produced by the tires rolling on the steel rollers generally interferes with the drive noise measurements performed at these test benches. For this reason, it is often necessary to take measures here to reduce the tire noise component.
These problems do not occur if the torque at the drive axles is transferred directly to a dynamometric brake via a connecting shaft. To enable this, the differential must be blocked and the other drive shaft must be removed. In addition, the rim at the drive wheel must be cut out at the center to allow connecting the connecting shaft with the drive shaft of the vehicle. In addition, the modified rim must be connected again with the hub carrier via a mounting (e.g. via the brake mounting).
By controlling the dynamometric brake and the drive pedal setting of the experimental vehicle, any operating point of the vehicle engine can be set. In this way, certain noise phenomena at the test bench can be approached more purposefully than on the road. The test bench is suitable for interior as well as exterior noise measurements. In addition, drivetrain vibrations can be investigated.
For special problems, it can be advantageous if the engine is separated from the chassis and supported on the test bench floor. This allows separating the structure-borne and airborne noise component in the interior noise. Results show here, for example, that the structure-borne noise component should no be underestimated.
The test bench is suited for passenger cars and lightweight trucks.
