Active Sound Absorbers

An active sound absorber for an exhaust system of an internal combustion engine, preferably of a motor vehicle, comprising at least one pressure equalization chamber, which surrounds an equalization volume, wherein at least one connecting line fluidically connects the equalization volume with a front volume, wherein at least one passive membrane is provided, which on the one hand is exposed to the pressure prevailing in the equalization volume and on the other hand is exposed to the pressure prevailing in a back volume.

An active sound absorber for an exhaust system of an internal combustion engine, preferably of a motor vehicle, comprising a sensor arrangement for measuring a pressure difference between a front volume and a back volume, wherein a control, provided for activating the actuator, is coupled with the sensor arrangement and activates an actuator as a function of the measured pressure difference for compensating a deflection of the active membrane caused by the pressure difference.

An active sound absorber for an exhaust system of an internal combustion engine, preferably of a motor vehicle, comprising a device for determining a deflection of an active membrane from its central position, wherein a control, provided for activating an actuator, is coupled with the device and activates the actuator as a function of the determined membrane deflection for compensating the membrane deflection.

An active sound absorber for an exhaust system of an internal combustion engine, preferably of a motor vehicle, comprising, a conveying device fluidically connected with a back volume, wherein a control, coupled with the conveying device, activates the conveying device as a function of a pressure difference between a front volume and the back volume, or as a function of a deflection of an active membrane from its central position for reducing the pressure difference and the membrane deflection for drawing in from the back volume or for conveying into the back volume.