Abstract:
A solid state drag reducing vehicle grille for a vehicle includes a front bumper carried by the vehicle, left and right grille portions carried by the vehicle situated above the front bumper, and slats carried by the left and right grille portions wherein the slats are adapted to allow air to flow through at low vehicle speeds and to partially redirect airflow at high vehicle speeds.

Description:
BACKGROUND OF INVENTION  
         [0001]    The present invention relates to vehicle grilles, and more specifically, to a solid-state drag reducing vehicle grille.  
           [0002]    Automotive vehicles typically have a radiator for cooling the engine. The radiator is commonly situated behind a grille. The grille permits air to flow through and to the radiator as the vehicle moves forward, thus providing an engine cooling benefit. More specifically, vehicle grilles allow oncoming air to flow through to contact and cool the radiator fins, which in turn cool the radiator fluid that cools the engine.  
           [0003]    Typically, the location and size of the grille are preferably designed to meet the low speed cooling requirements. The engine cooling requirements are only marginally higher with increased vehicle speed. However, as the vehicle velocity increases so does the amount of airflow into the engine compartment, which slows the vehicle and makes the engine work harder.  
           [0004]    The additional airflow at higher vehicle speeds is also detrimental to fuel economy. As vehicle velocity increases, the amount of vehicle aerodynamic drag as a result of the increased airflow into the engine compartment increases. As aerodynamic drag increases, more energy is required to move the vehicle.  
           [0005]    To compensate for these detriments, grille covers have been employed in the past to limit the amount of airflow into the engine compartment. However, this approach requires physical manipulation by the operator and has been used mainly on heavy-duty trucks to limit the amount of cold air into the engine compartment. Active grille shutters have also been used in the past to remedy these problems. Such a design is very costly and uses moving shutters, which are controlled by the engine, to actively limit the amount of air allowed into the engine compartment. These designs are complex and prone to failure over time.  
           [0006]    It is therefore desired to have airflow through the grille at low and high vehicle speeds to cool the engine, but to redirect the excess airflow that occurs at high vehicle speeds that is not needed. It would therefore be beneficial to have a passive vehicle grille system with a solid-state design having no moving parts that allows sufficient airflow at lower speeds while actively managing airflow at higher speeds, thereby reducing aerodynamic drag and improving fuel economy and vehicle stability. High cost and complexity are also overcome with such a passive system.  
         SUMMARY OF INVENTION  
         [0007]    It is an object of the present invention to provide a solid-state drag reducing vehicle grille that overcomes the disadvantages of the prior art.  
           [0008]    It is a feature of the present invention that the solid state drag reducing vehicle grille&#39;s slats have predetermined angles and lengths to allow normal airflow through the grille at lower vehicle speeds while actively redirecting airflow up and over the hood at high vehicle speeds, thereby reducing drag and improving fuel economy.  
           [0009]    The present invention advantageously provides a solid state drag reducing vehicle grille for a vehicle including a front bumper carried by the vehicle, left and right grille portions carried by the vehicle situated above the front bumper, and slats carried by the left and right grille portions wherein the slats are adapted to allow air to flow through at low vehicle speeds and to partially redirect airflow at high vehicle speeds. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0010]    These and other objects, features, and advantages of the present invention will become apparent from a reading of the following detailed description with reference to the accompanying drawings, in which:  
         [0011]    [0011]FIG. 1 is a perspective view of a vehicle with a solid-state drag reducing vehicle grille according to the present invention;  
         [0012]    [0012]FIG. 2 is a cross-sectional view along line  2 - 2  of FIG. 1 of a solid-state drag reducing vehicle grille according to the present invention;  
         [0013]    [0013]FIG. 3 is a cross-sectional view of a solid state drag reducing vehicle grille showing airflow at low vehicle speeds according to the present invention; and  
         [0014]    [0014]FIG. 4 is a cross-sectional view of a solid-state drag reducing vehicle grille showing airflow at high vehicle speeds according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0015]    In FIG. 1, a vehicle  10  having a hood  12 , a front bumper  14 , and headlights  16  is shown. Situated between the headlights  16 , above the front bumper  14 , and below the hood  12  is a solid-state drag reducing vehicle grille  18 . The solid-state drag reducing vehicle grille  18  is situated in front of a radiator (not shown). The solid-state drag reducing vehicle grille  18  allows airflow through and to the radiator to meet cooling requirements for the vehicle  10  at different speeds.  
         [0016]    A closer look at the solid-state drag reducing vehicle grille  18  can be seen in FIG. 2. The front bumper  14  has an upper surface  20  from which an upwardly and forwardly directed fin  22  of predetermined thickness extends a predetermined distance. The components thereafter that comprise the solid-state drag reducing vehicle grille  18  are a series of a predetermined number of slats  24 . From the fin  22 , the first slat  24  is situated a predetermined distance above and a predetermined distance rearward of the fin  22 . From the first slat  24 , the second slat  24  is then situated a predetermined distance above and a predetermined distance rearward of the first slat  24 , and so on, up to the last slat  24 . The last slat  24  is situated such that a top surface  26  of the hood  12  is a predetermined distance above and a predetermined distance rearward of the last slat  24 .  
         [0017]    The slats  24  are substantially L-shaped in cross-section and each has a lower portion  28  and an upper portion  30 . In cross-section, other shapes are possible, such as a curved shape, without departing from the scope of the present invention. The lower portions  28  have a front end  32  from which the lower portions  28  extend upwardly and rearward a predetermined distance. The lower portions  28  have a rear end  34  from which the upper portions  30  extend upwardly and forwardly a predetermined distance less than the lower portions  28 . As seen in FIG. 1, the slats  24  extend the entire length of the solid state drag reducing vehicle grille  18 , and are each connected to a left grille portion  36  and a right grille portion  38  so that the slats  24  and the left and right grille portions  36  and  38  are combined to form the one-piece solid-state design of the solid state drag reducing vehicle grille  18 .  
         [0018]    The specific passive design of the solid state drag reducing vehicle grille  18  allows for two different directions of airflow depending on vehicle  10  speed, while the solid state drag reducing vehicle grille&#39;s  18  geometry never changes. FIG. 3 shows airflow direction at low vehicle  10  speeds when airflow needs to travel through the solid state drag reducing vehicle grille  18  in order to reach the radiator to maintain vehicle  10  cooling requirements. The arrows indicate airflow. At low vehicle  10  speeds, airflow travels between the slats  24  to reach the radiator.  
         [0019]    At higher vehicle  10  speeds, the extra oncoming airflow does not need to pass through the solid-state drag reducing vehicle grille  18  to reach the radiator to cool the engine. Because of the specific design of the solid state drag reducing vehicle grille  18 , the airflow passing through the slats  24  at high vehicle  10  speeds is only marginally more then at low speeds. Instead, referring to FIG. 4, when air hits the fin  22 , the majority of air is pushed upward past the first slat  24  opening as shown by the arrows. As the air moves upward towards the lower portion  28  of the first slat  24 , oncoming air pushes it into a stagnation area  40  created where the upper portion  30  and lower portion  28  of the slat  24  meet. This air pools and is then forced directly upward past the second slat  24  opening as shown by the arrows. This air then combines with oncoming air and it then pools in the stagnation area  40  of the next slat  24 , and so on as shown by the arrows. When the air is pushed upward out of the stagnation area  40  of the uppermost slat  24 , the air then goes over the top surface  26  of the hood  12 .  
         [0020]    While the majority of the oncoming airflow as a result of this pooling action is redirected at high vehicle speeds, a small amount does pass through the slats  24  of the solid-state drag reducing vehicle grille  18 . Thus, the specific angles and lengths of the slats  24  of the solid state drag reducing vehicle grille  18  allow sufficient airflow at lower vehicle  10  speeds while actively managing, or redirecting, unneeded airflow at higher vehicle  10  speeds, thereby reducing aerodynamic drag and increasing fuel economy.  
         [0021]    While only one embodiment of the solid state drag reducing vehicle grille of the present invention has been described, others may be possible without departing from the scope of the following claims.