Abstract:
An instrument panel is provided for use in a vehicle interior. The instrument panel includes an outer surface, a vent and a step. The vent is arranged along the outer surface to direct forced air toward a specific area of a window in the vehicle. The step is formed along the outer surface of the instrument panel to promote formation of a turbulent buffer that reduces adhesion between air exiting the vent and the outer surface.

Description:
FIELD OF THE INVENTION 
     The invention relates to an instrument panel vent for an automotive vehicle. More particularly, the invention relates to an instrument panel design that reduces adhesion between air exiting the vent and an outer surface of the instrument panel. 
     BACKGROUND OF THE INVENTION 
     Vehicles typically include vents built into or formed in the instrument panel for directing forced air onto specific areas of a window or windshield in the vehicle. Modern instrument panels often have outer surfaces that are gently sloping or otherwise horizontal relative to the vents, which often results in adhesion between the air exiting the vent and the outer surface of the instrument panel. This results in air being drawn to areas other than the intended specific area of the window or windshield. Thus, it remains desirable to provide an improved design that eliminates the issue of adhesion between air exiting the vent and the outer surface of the instrument panel in order to improve the flow of air toward the intended specific area of the window or windshield in the vehicle. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, an instrument panel is provided for use in a vehicle interior. The instrument panel includes an outer surface, a vent and a step. The vent is arranged along the outer surface to direct forced air toward a specific area of a window in the vehicle. The step is formed along the outer surface of the instrument panel to promote formation of a turbulent buffer that reduces adhesion between air exiting the vent and the outer surface. 
     According to another aspect of the invention, a vehicle includes a window, a duct and an instrument panel. The duct provides forced air to be directed toward a specific area of the window. The instrument panel has a vent directing the forced air from the duct toward the specific area of a window. The instrument panel has an outer surface that extends between the vent and the specific area of the window. The instrument panel further has a step formed between the vent and the outer surface of the instrument panel, to promote formation of a turbulent buffer that reduces adhesion between air exiting the vent and the outer surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of an interior of a vehicle illustrating an instrument panel according to one embodiment of the invention; and 
         FIG. 2  is a cross sectional view of the instrument panel shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , an instrument panel is indicated at  10 . The instrument panel  10  includes an air vent  12  that directs forced air toward a side window  14  of a door  16 . The air vent  12  includes a lower wall  12   a  opposite an upper wall  12   b , and a pair of opposing side walls  12   c ,  12   b  each extending between the lower and upper walls  12   a ,  12   b  so as to form an opening. The vent  12  further includes a plurality of slats  20 ,  22  that help to guide the air toward a targeted area of the side window  14 , particularly near a side view mirror  18 . Each of the slats  20 ,  22  has a planar surface  20   a ,  22   a , and an upstream edge  20   b ,  22   b  opposite a downstream edge  20   c ,  22   c . The upstream edges  20   b ,  22   b  are disposed within the air vent  12 . In conventional instrument panel designs, air flow from the vent  12  will typically “adhere” or flow along a leading outer surface  24  of the instrument panel  10 . Adhesion causes the air to flow generally from the exit of the vent  12  along a path, as illustrated by the arrow B, away from the targeted area of the side window  14 . To reduce or eliminate adhesion between the flow of air exiting the air bent  12  and a leading outer surface  24  of the instrument panel  10 , a raised lip or step  30 , also referenced herein as a wall  30  is provided adjacent the vent  12 . The step  30  causes the air flow to follow a desired path, as illustrated by the arrow A, toward the targeted area of the side window  14 . 
     Referring to  FIGS. 1 and 2 , the step  30  is raised relative to the bottom slat, also referenced herein as the end slat  22 . More specifically, the end slat  22  is recessed below the lower wall of the vent  12 , and the step  30  is disposed on the downstream edge  22   c  of the end slat  22 . The step  30  interconnects the end slat  22  with the outer surface of the instrument panel, wherein a surface of the lower wall  12   a  of the vent  12  is substantially flush with an outer surface of the instrument panel. The step  30  operates to interfere with the air flow from the vent  12  and thereby create a turbulent buffer along the exit of the vent  12 . The formation of the buffer reduces or eliminates boundary effects and surface adhesion between the air flow and the outer surface  24  of the instrument panel. The step  30  extends longitudinally along the width of the vent  12  to maximize air flow toward the targeted area of the side window  14 . The height H of the step  30  is predetermined and can range between 2 mm to 4 mm relative to the bottom slat  22 . The height H of the step  30  generally depends on the difference between the approach angle of a duct  40 , which carries the forced air to the vent  12 , and the angle of the leading outer surface  24  of the instrument panel  10 , which is disposed on an opposite side of the step  30  relative to the vent  12 . This difference in angle is indicated at α in  FIG. 2 . A larger angle α allows for a smaller step height H. Conversely, a smaller angle α requires a larger step height H. 
     Alternatively, the step may be positioned spaced apart from the vent, such that the height of the step is determined relative to the outer surface instead of the bottom slat. 
     In one embodiment, wherein the angle α is approximately 21 degrees, a step height H of approximately 3 mm results in a substantial reduction or elimination of adhesion between the air flow from the vent  12  and the leading outer surface  24  of the instrument panel  10 . In general, a lip or a step along the exit of the vent  12  is desired where the angle α is less than approximately 26 degrees. 
     Although only one side of the vehicle is shown in the figures, it should be readily appreciated by those having ordinary skill in the art that the arrangement described above is applicable to both sides of the vehicle. This arrangement may also be used in other locations in the vehicle where it is desired to eliminate the effects of adhesion between the air flow exiting a vent and an adjacent outer surface in order to ensure proper air flow to a desired area of the vehicle. 
     The invention has been described in an illustrative manner. It is, therefore, to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Thus, within the scope of the appended claims, the invention may be practiced other than as specifically described.