Patent Application
20060211355
This invention relates to an air duct for motor vehicles having a flow longitudinal axis and at least one duct wall, at least partially encasing the flow longitudinal axis in the circumferential direction.
German document DE 1430918 discloses a ventilation device for vehicles, in particular motor vehicles, with ventilation openings, which are arranged in the windows or door frames, which are of at least partially hollow design, and which connect the interior of the vehicle to the outside air. The air flowing through the interior of the vehicle enters the cavity through the openings during the journey, flows upward within the door frame on both sides and exits again from the cavity through openings.
It is known from German document DE 195 21 192 A1 that outgoing air flows out of the interior of the passenger cell in the region of the windows through the side walls behind the ceiling covering and from there through apertures into the further ducts of the roof closing panel, which ducts are used for guiding outgoing air. The air is therefore guided, on the one hand, by covering parts and, on the other hand, by ducts provided for this purpose.
One object of the present invention is the object of designing and arranging an air duct in such a manner that a simple, partially optimized construction and a noise-optimized use are ensured.
This object is achieved according to the invention by way of a duct wall which has a first duct wall section and at least one second duct wall section, and by having the first duct wall section at least partially formed by a covering element and the second duct wall section at least partially formed by a car body element.
The effect achieved by this is that resolution of the conflict between the aims of a functioning ventilation of the vehicle interior, the acoustics of the vehicle interior and the use of components which, as far as possible, are multifunctional and lightweight is ensured. The integration of the air duct into the interior covering makes it possible to avoid additional sections for the duct. In addition, the covering parts and their properties can be at least partially used in order to optimize the development of noise in the passenger interior.
For this purpose, it is advantageous for the first duct wall section to be able to be placed against the second duct wall section in a connectable and sealing manner in the circumferential direction with respect to the flow longitudinal axis. Both duct wall sections surround the flow longitudinal axis or the flow main axis and therefore form an air duct which is closed around the flow longitudinal axis. The cross-sectional shape of the air duct may be designed here as desired. Provision is also made for the cross section to change with respect to the flow longitudinal axis or flow direction. An optimum transportation of air is therefore firstly ensured, and secondly a development of noise coming from the air duct into the passenger interior is prevented.
According to one development, an additional possibility is for the inside in each case of the first duct wall section and/or of the second duct wall section to have at least one acoustically active layer. The use of an acoustically active layer optimizes or reduces the input of sound emanating from the air duct into the passenger interior.
Furthermore, it is advantageous for the inside of the first duct wall section and/or of the second duct wall section to have a first acoustically active layer and at least one second acoustically active layer which is superimposed or arranged on the first acoustically active layer. The use of a plurality of acoustically active layers which are arranged one above another ensures an optimum coordination of the acoustic insulation.
It is also advantageous for the first acoustically active layer to have a larger volume weight than the second acoustically active layer, and for the first acoustically active layer to be designed as a high-pass filter with respect to the noise frequency and for the second acoustically active layer to be designed as a low-pass filter. The use of different volume weights for the acoustically active layers makes it possible for account to be taken of the frequency band which is generated in the air duct and transmitted by the air duct. The acoustically active layer with the greater volume weight, i.e. with the greater density, will prevent medium and low frequencies from being irradiated acoustically from the air duct into the passenger interior. It is used as a high-pass filter. Corresponding to this, the use of acoustically active layers with a low volume weight, i.e. with low density, leads to the absorption of high-frequency components of the acoustic stream to be absorbed. They are therefore used as low-pass filters.
According to one preferred embodiment of the invention, provision is finally made for a sealing element to be provided between the first duct wall section and the second duct wall section. The use of an additional sealing element ensures that the air duct is soundproof.
In conjunction with the design and arrangement according to the invention, it is advantageous that at least one releasable connecting element is provided between the first duct wall section and the second duct wall section. The releasable connecting elements are used for the simple and rapid installation and the correspondingly simple and rapid removal of the covering elements or of the duct wall sections.
It is furthermore advantageous for the first duct wall section to have two sides which can be placed with their end faces onto the second duct wall section. The flow longitudinal axis is therefore entirely surrounded by the air duct in the circumferential direction.
In addition, it is advantageous for the first duct wall section to be of L- or U-shaped design in cross section, and for sides thereof to run, with respect to the flow cross section, approximately parallel to the second duct wall to form two limbs of the profile.
Further advantages and details of the invention are apparent from the patent claims, explained in the description, and illustrated in the figures.
The air duct 1 which is illustrated in
The first duct wall section 3.1 is likewise L-shaped in cross section with a first limb 3.3 and a second limb 3.3′. The two limbs 3.3, 3.3′ bear in this case with their end faces against the second duct wall section 3.2 and against the car body element 5.
The first duct wall section 3.1 is formed from a covering element 4 which has a first acoustically active layer 6.1 on the inside of the air duct 1, and a second acoustically active layer 6.2 above it. The two acoustically active layers 6.1, 6.2 arranged one above the other are likewise of L-shaped design in cross section in accordance with the L shape of the covering element 4. And they butt with their respective end faces against the car body element 5.
The first acoustically active layer 6.1 is of substantially thinner design here than the second acoustically active layer 6.2 and also has a greater density than the second acoustically active layer 6.2.
At the end of the second limb 3.3′, the covering element 4 has a closing element 3.4 which permits the point of abutment between the covering element 4 and the car body element 5 to taper at an acute angle.
The covering element 4 which is illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 10 651.0 | Mar 2003 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP04/02110 | 3/3/2004 | WO | 2/7/2006 |
