The present invention relates to a sliding roof system for a motor vehicle, with a sliding roof opening, which is provided in a vehicle roof curved transversely with respect to a longitudinal axis of the motor vehicle and has a front sliding roof edge and a rear sliding roof edge and a wind deflector which, when the sliding roof is open, is provided in the region of the front sliding roof edge, the wind deflector having over its entire length at least one profile section designed with a wing profile and the profile section being assigned a profile axis arranged transversely with respect to the longitudinal axis of the motor vehicle.
The wind deflector is used to avoid air flowing through the sliding roof opening into the vehicle interior. An air flow of this type causes annoying pressure resonances which are referred to as rumbling. The cause of the rumbling is an eddy which becomes detached at the front sliding roof edge and, depending on the opening length, the roof envelope and the overflow conditions, periodically enters the passenger compartment at the rear sliding roof edge and therefore leads to pressure fluctuations.
Wind deflectors are disclosed in FR-2694522 and U.S. Pat. No. 5,630,640 for motor vehicles, which both run rectilinearly with respect to the longitudinal axis, which intersects the transverse axis at an angle, i.e. are not curved. However, the wind deflector according to U.S. Pat. No. 5,630,640 is of curved or concave design with respect to the transverse axis over its entire length.
An openable roof construction for a vehicle with a roof opening formed in the roof of the vehicle has furthermore been disclosed in DE 101 17 364 A1. The roof opening can be closed by a panel, with a wind deflector being arranged in the vicinity of the front edge of the roof opening in order to deflect an air flow, which is essentially directed rearward over the roof of the vehicle, in relation to the roof opening. The wind deflector is provided with an upper surface which is approached by the flow and has a concave profile in the vicinity of the rear edge of the wind deflector. The wind deflector comprises a main part and a flap-shaped auxiliary deflector. The main part and the auxiliary deflector are at such an angle with respect to each other that a concave profile is again realized. The axis of curvature of this concave surface likewise extends over transversely with respect to the longitudinal axis of the vehicle. The wind deflector is arranged at a distance above the roof of the vehicle, so that an air flow passage is likewise produced along the lower side of the wind deflector.
An object of the present invention is to provide a wind deflector in such a manner that the wind deflector can be matched aerodynamically to a particular vehicle body and the air flow is conducted rearward beyond the rear sliding roof edge even in the region of the lateral sliding roof edges.
The foregoing object has been achieved according to the invention by the fact that at least two profile sections are provided which are designed with a wing profile and are torsionally distorted with respect to each other at an angle (α) about the profile axis extending transversely with respect to the longitudinal axis of the motor vehicle. The wind deflector therefore has a torsional distortion which is symmetrical with respect to its center. The effect achieved thereby is that the flow over the width of the wind deflector and therefore over the width of the sliding roof opening is deflected to differing extents. It is possible, by way of the differing deflection precisely in the edge region of the sliding roof opening, to conduct the air flow beyond the rear sliding roof edge.
For this purpose, it is advantageous that at least two profile sections have sides curved concavely and/or convexly to differing extents as a function of the particular distance of the profile axis from the vehicle roof, which sides are torsionally distorted with respect to each other at an angle (α) about the profile axis (3.5) extending transversely with respect to the longitudinal axis of the motor vehicle. This also makes it possible, by means of the differing deflection, to conduct the air flow to different extents in width beyond the rear sliding roof edge even in the region of the lateral sliding roof edges.
The efficiency of the wind deflector is improved by the twisted torsional distortion and by the sides curved concavely and/or convexly to differing extents. This enables the wind deflector to have smaller dimensions or to permit larger sliding roof openings, since the air flow can be conducted rearward further than in the case of wind deflectors which are already known.
Furthermore, it is advantageous that a supporting device of the wind deflector has at least one supporting arm which connects the wind deflector to the vehicle roof, and the supporting arm has at least one turbulator which is designed as a stud, notch or opening and is arranged on one side of the supporting arm.
The sides of the sliding roof opening generally run perpendicularly with respect to the front or rear sliding roof edge. Since the wind deflector can be retracted within the sliding roof opening, its maximum length is the width of the sliding roof opening. In the case of conventional wind deflectors, this still causes at least some of the air flow to flow through the sliding roof opening into the interior, which once again leads to a rumbling.
The rumbling can be completely eliminated by the design according to the invention of the supporting device. The supporting device, which is optimized in terms of flow and has turbulators, assists in disturbing coherent flow detachments in the lateral sliding roof region and therefore the air flow flowing in laterally cannot cause periodic fluctuations in pressure.
An additional possibility, according to one development, is that the sliding roof system is combined in such a manner that the wind deflector has a torsional distortion and sides curved to differing extents or has a supporting device with turbulators. For large sliding roof openings, the combination of a wind deflector which is torsionally distorted in a twisted manner, has sides curved to differing extents and has a supporting device with turbulators is advantageous, since a flow which is deflected further rearwards in accordance with the position with respect to the vehicle roof is promoted.
It is also advantageous for this purpose for the two profile sections to be torsionally distorted by an angle with respect to each other as a function of the particular distance of the profile axis from the vehicle roof. Vehicle roofs are frequently of curved design transversely with respect to the longitudinal axis of the vehicle. As a result, the distance of the profile axis from the vehicle roof has a direct effect on the flow and its range over the sliding roof opening. By means of a torsional distortion of the wind deflector as a function of the distance from the vehicle roof, the air flow is matched individually to the motor vehicle or to the shape of the vehicle roof.
According to one current preferred embodiment of the solution according to the invention, it is finally provided that the length of the wind deflector is 5 to 25% shorter than the front length of the sliding roof edge and the supporting arm at least partially has a cross-sectional profile which is designed as a wing profile. This creates the possibility of arranging the supporting arm not in a plane perpendicular with respect to the vehicle roof, but rather in a plane which encloses an angle of less than 90° with respect to the vehicle roof. In such a position, the supporting arm, in the design according to the invention, assists in conducting the flow over the sliding roof opening. A similar effect is produced by a wind deflector which is of bow-shaped design and is provided over the entire width of the sliding roof opening. Although the flow is no longer deflected vertically upward in the edge region of the sliding roof opening, it has at least one vertical component for spanning the sliding roof opening.
Of particular importance for the present invention is that turbulators which are in the form of depressions, recesses, interfering edges or superelevations are provided on at least one side or in the region of a separation flow line of the wind deflector. These turbulators, which are generally provided on the lower side of the wind deflector, can be very readily combined with the measures which are described above and which increase the reach of the flow over the sliding roof opening. The turbulence generated on the surface of the wind deflector by the interfering edge or depressions consequently has a turbulent boundary layer which, in turn, enables the pressure rise caused by the flow over a convexly curved surface to be better overcome. Thus, a possibly premature, pressure-driven flow detachment is shifted downstream to the rear edge of the profile as what is referred to as a shape-driven flow detachment.
It is furthermore advantageous that the wind deflector can be moved from an operating position with the sliding roof at least partially open, by pivoting about an axis of rotation fixed with respect to the vehicle roof, into a position, in which the sliding roof can be at least partially or completely closed. An additional translatory movement of the wind deflector and a correspondingly complicated mechanism are dispensed with. The wind deflector is in a fixed position with respect to the supporting arm. The axis of rotation is arranged below the plane in which the sliding roof is mounted such that it can move in a translatory manner.
It is also advantageous that a spring and damping element is arranged between the supporting arm and the vehicle roof, the spring and damping element exerting a force on the wind deflector which sets the wind deflector into its operating position and varies the operating position of the wind deflector as a function of the air speed. The supporting arm is prestressed in the active position of the wind deflector via the telescopic spring and damping element.
The flow deflection and the distribution of pressure vary as a function of the air speed at the wind deflector. A force component resulting in a correspondingly variable manner acts on the wind deflector in the direction of the vehicle roof. At higher driving speeds, the wind deflector is therefore continuously lowered from its starting position optimized with respect to the rumbling into a position situated lower with respect to the vehicle roof, which results in a significant reduction in the wind noises. For this, the spring and damping element is configured in such a manner that the wind deflector, in its height with respect to the vehicle roof, is matched dynamically to the driving speed. In all cases, the flow is conducted over the sliding roof opening. At low speeds, the wind deflector rises again after being lowered.
It is furthermore advantageous for the supporting arm of the wind deflector to be pressed down by the sliding roof when the sliding roof is closed. The front edge of the sliding roof moves above the axis of rotation of the wind deflector, during closure of the sliding roof, onto the supporting arms provided on both sides of the wind deflector, as a result of which said supporting arms fold over or pivot forward in the direction of the movement of the sliding roof. The supporting device and the wind deflector are therefore brought into a position below the sliding roof, making it possible for the sliding roof to close.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
Above the sliding roof opening 2, a wind deflector 3 is fastened rigidly to a supporting arm 5.1 of a supporting device 5. The supporting arm 5.1 is mounted on the vehicle roof 9 in a manner such that it can rotate via a rotation axis 5.4 and is upwardly supported via a prestressed spring and damping element 5.3, which is likewise fastened to the vehicle roof 9. The rotation axis 5.4 is assigned to a hole in a receptacle on the vehicle roof 9 and is fixed in its position. The rotation axis 5.4 cannot be displaced in a translatory manner.
The wind deflector 3 is airfoil-shaped and has a concave upper side 3.2 and a convex lower side 3.3. A profile section 3.1 and a profile section 3.1′ are illustrated in
As illustrated in
According to
The spring and damping element 5.3 is telescopic and supports the wind deflector 3 upwardly. The supporting arm 5.1 is pressed down by the sliding roof 1.1 when the sliding roof 1.1 is closed, and pivots downward about the profile axis 3.5 illustrated in
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
Number | Date | Country | Kind |
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10309395.8 | Mar 2003 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP04/01899 | 2/26/2004 | WO | 1/18/2006 |