Abstract: In an air filter system for an internal combustion engine having a fresh air line with an air inlet, a filter housing with an upper housing half and lower housing half, a filter element disposed in the filter housing, a clean air outlet opening with an adjoining clean air line opening into the intake system of the internal combustion engine, and means for damping intake noise, the means for damping the intake noise is a sheet configured and arranged adjacent, and clamped to, the upper housing half opposite the clean air outlet whereby the intake noise vibration energy is absorbed by frictional relative movement between the sheet and the upper housing half, the intake noise being damped by a change in impedance, in particular by a jump in impedance.

Abstract: In an air filter system for an internal combustion engine comprising a fresh air line with an air inlet, a filter housing with an upper housing half and lower housing half, a filter element disposed in the filter housing, a clean air outlet opening with an adjoining clean air line opening into the intake system of the internal combustion engine, and means for damping intake noise, the means for damping the intake noise is configured and arranged in such a way that, on the other hand, the intake noise is absorbed by joint patch damping and, on the other hand, the intake noise is damped by a change in impedance, in particular by a jump in impedance.

Abstract: In a vibration dampening support arrangement for supporting a component on a support structure such that it is removable only in a predetermined direction of removal, a projection extends from the support structure at an angle .alpha. of 12.degree. to 60.degree. with respect to the direction of removal and an elastic element is disposed on the projection in form-locking engagement with the component in the predetermined direction of removal but is unreleasably held in any other direction.

Abstract: An exhaust manifold for an internal combustion engine includes an inner duct with flanges for connection to an engine. The inner duct is enclosed by an envelope consisting of two shells which are interconnected at their edges by seams. Between the inlet flanges, the seams are disposed at a substantially greater distance from the inner duct than in other areas such that, in a cross-sectional plane disposed between, and extending normal to, the flanges, the envelope has drop-like shape.

Abstract: In a flow deflector structure for an intake air duct of an internal combustion engine which includes a housing with air inlet and outlet openings arranged at a predetermined angle with respect to each other for redirecting air flowing through the deflector structure and with flow guide vanes curved according to the flow direction change provided by the flow deflector structure, the housing has a flow cross-section which is larger than the flow cross-section of the inlet and outlet openings and a side wall opening with a cover to facilitate forming, or insertion of the guide vanes in the housing.

Abstract: In an air intake system for an internal combustion engine having at least one cylinder with an intake pipe extending between the cylinder and an air collecting box for supplying intake air from the collecting box to the cylinder a diaphragm structure is arranged at the end of the intake pipe and includes an oscillation generator for providing acoustic pressure oscillations to the air in the intake pipe adapted to increase the cylinder air charge as a function of engine operating parameters and the intake air pipe is in communication with the air box via a connecting passage which includes a device for suppressing the acoustic pressure oscillations to prevent their transmission to the air in the air box.