Abstract:
A vehicle body ventilation system for a vehicle having a windshield, a hood, and a cowl assembly, wherein the cowl assembly comprises a cowl grille panel having a front and a rear edge and a first seal including a sealing portion and a carrier portion wherein the carrier portion is frictionally engaged with the front edge of the cowl grille panel. A second seal is provided that includes a sealing portion and a carrier portion wherein the carrier portion is frictionally engaged with the rear edge of the cowl grille panel. The carrier portion of the first seal and the second seal are of a first durometer and the sealing portion of the first seal and the sealing portion of the second seal each are of a second durometer for sealing to a vehicle windshield and hood, wherein the second durometer is less than the first durometer.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 60/436,912 filed Dec. 27, 2002. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to vehicle ventilation systems and more particularly to cowl assemblies that provide an inlet to the HVAC system of a vehicle and more particularly to snap-on seals which may be attached to the front and rear edges of the cowl grille panel to seal it against the vehicle windshield, hood or plenum chamber. 
     BACKGROUND OF THE INVENTION 
     Cowl assemblies for vehicles are located between the hood, windshield and fenders to close out that area and act as a grille to cover the air inlet plenum that feeds air to the HVAC system of the vehicle. The cowl grille panel is usually injection molded of plastic and sits above the air plenum for the HVAC system. The cowl grille panel seals off against the vehicle windshield at the rear edge of the grille panel to prevent water leakage. Normally, a separate seal is used between the vehicle hood and a vehicle cross-member to prevent noise and fumes from the engine from entering the passenger compartment. 
     Various types of seals have been used in the past on cowl panels, often made of elastomeric or plastic materials, which are adhesively or mechanically attached to the cowl panel. This type of attachment represents a labor intensive assembly process and, over time, the adhesive used can age and lose it bond to the cowl panel. 
     U.S. Pat. No. 5,108,146 to Jonathan L. Sheppard discloses a cowl grille to windshield lip seal, the seal including a U-shaped portion and a lip portion with the inner surface of the U-shaped portion of the seal formed as to be complementary in shape and snap about the outer surface of the grille rear edge. Further, the lip seal comprises a dual durometer elastomeric material with the seal body (U-shaped) portion being harder than the lip portion. The rear edge portion of the cowl grille panel is molded in a much thinner cross-section than the body of the cowl grille panel, thus requiring significantly higher injection molded machine tonnage (clamp) forces to fill out the thin section of the cowl grille panel. 
     U.S. Pat. No. 5,251,954 to Kopple, et al. discloses a vehicle cowling which includes a seal which is integrally molded to the cowl body in a dual injection molding process wherein the mold cavity is first filled with a thermoplastic, such as 20% glass filled polypropylene. A slide core is first protracted in the mold cavity and after the fist shot of plastic, the slide core is retracted to form a space for a second shot of thermoplastic rubber (TPR) to form the integral seal. The seal of TPR, being softer than the cowl body, conforms to the shape of the windshield. 
     U.S. Pat. No. 6,213,541 to Razgunas, et al. assigned to the assignee of the present invention, and included herein by reference, discloses a two piece cowl assembly for a vehicle in which the two cowl parts have an edge segment and a seal member carried by said edge segment which has a sealing flap therein configured to seal against the outer surface of a windshield. The seal member has a hard and soft end, the hard end being connected to the cowl edge. The elastomeric seal is a co-extruded seal having a base of a semi-rigid strip of polypropylene and a lip that is configured as a flap having greater flexibility or elasticity than the semi-rigid base strip. As in the &#39;146 patent, the cowl grille panel edge is much thinner than the body of the cowl grille panel, requiring additional clamp tonnage for the injection molding machine. Further, the fit of the seal to the cowl edge, while including complementary features between the cowl grille rear edge and the inner surface of the seal body, is desired to be loose such that the seal can slip along the edge of the two cowl grille parts to allow for lateral adjustment of the cowl grille parts relative to the seal. 
     U.S. Pat. No. 5,273,341, assigned to Ford Motor Co., discloses a sealing apparatus for providing a seal between the hood and the vehicle body structure. The rear edge of the vehicle hood includes a seal engaging member which engages an elastomeric strip which is located on a cross-rail member when the hood is closed. 
     What is therefore needed is a cowl assembly which includes seals such as snap-on seals for both the front and rear edges of a cowl grille panel, the seals being easily, yet securely installed. The snap-on seals should conform to the windshield to prevent water leakage and conform to the vehicle hood and/or plenum chambers to prevent both water and air leakage. 
     It is thus an object of this invention to provide snap-on seals for both the front and rear edges of a cowl grille panel to optimize assembly and performance. 
     It is further object to provide snap-on seals for a cowl grille panel which reduces the clamp tonnage required for the molding machine that molds the cowl grille panel. 
     It is a still further object of the present invention to provide a co-extruded seal having a rigid plastic carrier portion for secure retention of the seal to the cowl grille edge and a softer sealing portion to conform to opposing surface such as a vehicle hood, windshield or plenum, and which requires no additional fastening mechanism such as double-backed adhesive or mechanical fasteners. 
     It is still further object of the present invention to provide sealing shapes for the softer portion of the co-extruded seal which can compensate for uneven surfaces or loose fits of adjacent components. 
     It is still further object of the present invention to provide a cross-locking feature between the seal carrier portion and the cowl grille edge to increase pull-off forces of the mating parts and improve seal retention. 
     It is still further object of the present invention to provide a lip seal having an improved opposing moment which insures sealing against the opposing surface. 
     SUMMARY OF THE INVENTION 
     In a first embodiment the present invention is directed at a vehicle body ventilation system for a vehicle having a windshield, a hood, and a cowl assembly, wherein the cowl assembly comprises a cowl grille panel having a front and a rear edge, a first seal including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said front edge of said, cowl grille panel. A second seal is provided including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said rear edge of said cowl grille panel, wherein the carrier portion of said first seal and said second seal is of a first durometer and said sealing portion of said first seal and said sealing portion of said second seal each are of a second durometer, wherein said sealing portion of said first seal seals against a vehicle hood and said sealing portion of said second seal seals against a vehicle windshield, wherein said second durometer is less than said first durometer. 
     In a second embodiment the present invention is directed at a vehicle body ventilation system for a vehicle having a windshield, a hood, an air plenum, and a cowl assembly, wherein the cowl assembly comprises a cowl grille panel having a front and a rear edge and a first seal including a sealing portion for sealing against said air plenum and said hood and a carrier portion wherein said carrier portion is frictionally engaged with said front edge of said cowl grille panel. A second seal is provided including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said rear edge of said cowl grille panel, wherein the carrier portion of said first seal and said second seal is of a first durometer and said sealing portion of said first seal and said sealing portion of said second seal each are of a second durometer wherein said sealing portion of said first seal seals against a vehicle hood and air plenum and said sealing portion of said second seal seals against a vehicle windshield, wherein said second durometer is less than said first durometer. 
     In a third alternative embodiment the present invention is directed at a vehicle body ventilation system for a vehicle having a windshield, a hood, an air plenum, and a cowl assembly, wherein the cowl assembly comprises a cowl grille panel having a front and a rear edge and a first seal including a sealing portion for sealing against said hood and a carrier portion wherein said carrier portion is frictionally engaged with said front edge of said cowl grille panel and said air plenum. A second seal is provided including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said rear edge of said cowl grille panel, wherein the carrier portion of said first seal and said second seal is of a first durometer and said sealing portion of said first seal and said sealing portion of said second seal each are of a second durometer wherein said sealing portion of said first seal seals against a vehicle hood and said sealing portion of said second seal seals against a vehicle windshield, wherein said second durometer is less than said first durometer. 
     In a fourth alternative embodiment the present invention is directed at seals for sealing a cowl grille panel to a windshield and hood of a vehicle, said seals comprising a first seal including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said front edge of said cowl grille panel, and a second seal including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said rear edge of said cowl grille panel. The carrier portion of said first seal and said second seal is of a first durometer and said sealing portion of said first seal and said sealing portion of said second seal each are of a second durometer wherein said sealing portion of said first seal seals against a vehicle hood and said sealing portion of said second seal seals against a vehicle windshield, wherein said second durometer is less than said first durometer. 
     In a fifth alternative embodiment the present invention is directed at seals for sealing a cowl grille panel to a windshield, hood and air plenum of a vehicle, said seals comprising a first seal including a sealing portion for sealing against said air plenum and said hood and a carrier portion wherein said carrier portion is frictionally engaged with said front edge of said cowl grille panel and a second seal including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said rear edge of said cowl grille panel, wherein the carrier portion of said first seal and said second seal is of a first durometer and said sealing portion of said first seal and said sealing portion of said second seal each are of a second durometer wherein said sealing portion of said first seal seals against a vehicle hood and air plenum and said sealing portion of said second seal seals against a vehicle windshield, wherein said second durometer is less than said first durometer. 
     In a sixth alternative embodiment the present invention is directed at seals for sealing a cowl grille panel to a windshield, hood and air plenum of a vehicle, said seals comprising a first seal including a sealing portion for sealing against said hood and a carrier portion wherein said carrier portion is frictionally engaged with said front edge of said cowl grille panel and said air plenum, and a second seal including a sealing portion and a carrier portion wherein said carrier portion is frictionally engaged with said rear edge of said cowl grille panel, wherein the carrier portion of said first seal and said second seal is of a first durometer and said sealing portion of said first seal and said sealing portion of said second seal each are of a second durometer wherein said sealing portion of said first seal seals against a vehicle hood and said sealing portion of said second seal seals against a vehicle windshield, wherein said second durometer is less than said first durometer. 
    
    
     BRIEF DESCRIPTION OF THE INVENTION 
     FIG. 1 is a fragmentary perspective view of a vehicle embodying the cowl assembly of the present invention. 
     FIG. 2 is a perspective view of a cowl grille panel including the snap-on seals of the present invention. 
     FIG. 3 is an enlarged view of the right end of the cowl grille panel of FIG.  2 . 
     FIG. 4 is an enlarged cross-sectional view of one embodiment of the windshield seal of the present invention. 
     FIG. 4A is an enlarged cross-sectional view of an alternate embodiment of the windshield seal of FIG.  4 . 
     FIG. 4B is an enlarged cross-sectional view of an alternate embodiment of the windshield seal of FIG.  4 . 
     FIG. 5 is an enlarged cross-sectional view of one embodiment of the hood seal of the present invention. 
     FIG. 5A is an enlarged cross-sectional view of an alternate embodiment of the hood seal of FIG.  5 . 
     FIG. 5B is an enlarged cross-sectional view of an alternate embodiment of the hood seal of FIG.  5 . 
     FIG. 6 is an enlarged cross-sectional view of an alternate embodiment of the hood seal of the present invention. 
     FIG. 7 is an enlarged cross-sectional view of an alternate embodiment of the hood seal of the present invention. 
     FIG. 8 is an enlarged cross-sectional view of an alternate embodiment of the hood seal of the present invention. 
     FIG. 9 is an enlarged cross-sectional view of the hood seal of the present invention in an alternate embodiment, capturing the plenum front edge. 
     FIG. 10 is an enlarged cross-sectional view of the hood seal of the present invention in an alternate embodiment, capturing the plenum front edge. 
    
    
     In the appended drawings, common elements use the same numeric character but are distinguished by the addition of a letter to identify a common element between embodiments (for instance,  10 ,  10 A,  10 B, etc. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As noted above, the present invention is directed to a cowl assembly for a vehicle which preferably includes snap-on seals at both the front and rear edges of a cowl grille panel to seal against the windshield, hood and plenum chamber thereby reducing noise, water and air leakage. The snap-on seals may be co-extruded profiles in a number of shapes, having a more rigid, preferably plastic, carrier portion and a softer, preferably elastomeric, lip or sealing portion. The seals are easily snapped over complementary features of the cowl grille edge and seal at the cowl grille panel rear edge against the lower surface of the vehicle windshield and at the cowl grille panel front edge against the vehicle hood. In alternate embodiments, the front seal may also seal against the vehicle plenum chamber. Alternatively, the front seal may comprise a carrier portion which overlaps and connects together the cowl grille panel and the front edge of the plenum chamber. The softer sealing portion may comprise a lip portion having an enhanced moment or may comprise a hollow bulb seal which can fill in larger gaps or spaces between adjacent compartments. 
     Referring now to the drawings, FIG. 1 illustrates a vehicle cowl assembly  10  located between a windshield  12  and a hood  14  of a motor vehicle  16 . The cowl assembly  10  carries a seal unit  18  that is configured to seal a gap between the cowl grille panel  34  and the windshield  12  above a fire wall  20 . A pair of laterally spaced supports or connection points  22 ,  24  are provided on a vehicle part, e.g., the right and left vehicle fenders, for connection to opposite ends  26 ,  28  of the cowl assembly  10  by suitable fasteners such as plug nuts  30 ,  32  or other suitable fasteners depending upon the type selected by the manufacturer that is practicing the method of the present invention to apply the cowl assembly and seal unit of the present invention for its intended industrial application. The cowl grille panel  34  includes openings  40 ,  42  through which dual wiper arms  44  and blades  46  are reciprocally pivotally mounted on the cowl  34  for wiping the outer surface  48  of the windshield  12 . 
     As shown in FIG. 2, the cowl assembly  10  of the present invention includes a cowl grille panel  34  having an open grille area  38  for allowing air to enter a plenum for the HVAC unit (not shown) of the vehicle. The cowl grille panel  34  also includes two snap-on seals  18 ,  36  which mount on the rear and front edges  50 ,  52  respectively of the cowl grille panel  34 . The rear edge seal  18  conforms to the surface of the windshield  12 , while the front edge seal  36  conforms to the vehicle hood when it is in a closed position. 
     FIG. 3 is an enlarged view of the driver&#39;s side end of the cowl assembly  10 , showing one embodiment of the profile shape of the preferably co-extruded plastic/elastomeric snap-on seals  18 ,  36 . In this embodiment, the rear seal  18  is snapped over the rear edge  50  of the cowl grille panel  34 . The front seal  36  of the cowl grille panel snaps over the front edge  52  of the grille cowl panel and is preferably a co-extruded profile of plastic/elastomer which has an upstanding hollow “shark fin” cross-section to seal against the vehicle hood. Also shown are the opening  42  through which the driver&#39;s side windshield wiper can be mounted and a sponge rubber pad  60  that the hood  14  compresses when the hood  14  is closed. The cowl grille panel  34  is preferably injection molded of a rigid thermoplastic including, but not limited to, polycarbonate/ABS, polyphenylene oxide, talc-filled polypropylene or acrylonitrile styrene acrylate. 
     Turning to FIG. 4, one embodiment of the cowl grille panel rear snap-on seal  18  is shown in sectional view. The seal  18  is a preferably co-extruded profile comprising a carrier portion  62  and a lip portion  68 . This generally U-shaped profile  62  is preferably a rigid thermoplastic, such as 20% talc-filled polypropylene, and has features on its inner surface  64  that are complementary in shape to the outer surface features  66  of the cowl grille panel rear edge  50 . 
     With both the cowl grille panel  34  and carrier portion  62  of the seal  18  being rigid thermoplastic, by matching the features of the surfaces  64 ,  66 , a die locked condition is created between the carrier portion  62  and cowl grille panel  34  which assures a secure attachment with high pull-off forces. The lip portion  68  of the seal  18  is preferably a thermoplastic rubber (TPR) which is softer (lower durometer) than the plastic carrier  62  and co-extruded or molded to the carrier portion  62  to form a composite structure having two ranges of hardness, a harder carrier portion  62  for retention to the cowl grille panel  34  and a softer lip portion  68  for sealing against the windshield surface  48 . 
     In FIG. 4, the lip portion  68  of the seal  18  is shown in an as-molded condition (solid line) and in an assembled condition (dashed line) under compression with the windshield surface  48 . It is noteworthy that as shown in FIG. 4 the cross-sectional area of the cowl grille panel  34  near its rear edge  50  is kept constant and not reduced to allow for the snap-fit of the seal carrier portion  62 . This is important as this allows for a significant reduction in the clamp tonnage required for the injection molding machine that forms the cowl grille panel  34 . 
     FIG. 4A illustrates an improved condition over FIG. 4 in both seal retention and sealing. As can be seen in the circle indicated by arrow “B”, the surfaces  64 ,  66  have been elongated to form essentially a die locked condition at  70  between the carrier portion  62  of the seal  18  and the rear edge  50  of the cowl grille panel  34 . This provides additional retention of the seal  18  on the cowl grille panel  34  when the lip portion  68  of the seal  18  is rotated upward (direction of arrow A) as the lip portion  68  engages the windshield (not shown) and provides a greater moment for sealing against the windshield (note the angle of the lip portion with reference to the center line of the cowl grille panel  34 ). 
     FIG. 4B illustrates another alternate embodiment of the snap-on seal  18  which focuses the pressure for sealing the lip portion against the windshield as well as increased pull-off forces for the carrier portion. Here, a stabilizing bead  72  is formed at the tip of the lip portion  68  of the seal  18  which provides additional local pressure to conform the seal against the windshield and to stabilize the end of the seal  18  against movement at high vehicle speeds. In addition, an additional depression  74  is formed in the carrier portion  62  and matched against a complementary feature in the cowl grille panel  34  near its rear edge  50  to further lock (cross-lock) the seal  18  on the cowl grille panel  34  rear edge  50  and increase pull off force. 
     Turning to the hood seal  36  which snaps over the front edge  52  of the cowl grille panel  34  to seal to the vehicle hood  14 , FIG. 5 illustrates one embodiment of the present invention. The hood seal  36  is preferably a co-extrusion of a rigid plastic to form the U-shaped carrier section  80  which snaps over the front edge  52  and a softer seal portion  82 . In this embodiment, the seal portion  82  is shaped like a shark&#39;s fin and is a bulb or hollow seal capable of sealing fairly large openings. In this FIG. 5, the hood  14  is shown by a line as if it were closed to illustrate the amount of interference with the seal portion  82 . Being quite flexible, preferably of a thermoplastic rubber and hollow, the seal portion  82  prevents noise and fumes from escaping from the rear edge of the vehicle hood and entering the passenger compartment through the cowl grille panel openings and the plenum for the HVAC. Similarly, the seal prevents water from entering the engine compartment. 
     The carrier portion  80  of the hood seal  36  is formed of a more rigid plastic, as with the rear edge seal carrier portion  62  and has a U-shape with complementary features to those of the front edge  52  of the cowl grille panel  34  so that a snap-fit is created. In the embodiment shown in FIG. 5, a further feature of the hood seal  36  are protrusions  90 , preferably triangular, which extend downward from the bottom of the seal  36  to engage with complementary grooves  92  in the front lip  102  of the plenum  100  to provide additional sealing. This eliminates an additional path for the leakage of fumes from the engine compartment into the passenger compartment of the vehicle. In this embodiment, the triangular protrusions  90  are solid and formed of the softer seal material, preferably thermoplastic or even thermoset rubber, during the extrusion or molding process that forms the hood seal  36 . 
     FIG. 5A shows an alternate embodiment of the hood seal  36  where the triangular protrusions  90  are replaced with a bulb seal  94  of preferably circular, semi-circular or elliptical cross-section, in this case semi-circular. This hollow seal portion  94  may be preferred to seal larger gaps between the front edge  52  of the cowl grille panel  34  and the lip  102  of the plenum  100  (see FIG.  5 ). While the hood seal  36  may be formed such that the softer, preferably thermoplastic rubber material, completely may cover the outer surface of the carrier portion  80  (as shown in FIG.  5 ), it is also possible to form the softer sealing material in two portions, a shark-fin bulb seal portion  82  and a plenum seal portion  94  (see FIG.  5 A). This alternate construction provides material and cycle time efficiencies in the manufacturing process for the hood seal  36 , reducing cost. It should be noted that with the hood seal  36  of the present invention, as with the rear edge seal  18 , the cross-section of the cowl grille panel is kept constant at its front edge  52 , essentially equal to the thickness of the body of the grille panel, to minimize the clamp tonnage required when forming the grille panel  34 . 
     FIG. 5B illustrates a further example of this, as a still lower cost (less material required) hood seal is provided. 
     FIG. 6 illustrates an alternate embodiment of the hood seal  36  of the present invention which uses even less material. Here, the lip seal portion  82  is in the form of an extended beam member rather than the “shark fin” bulb portion of FIG. 5 (shown in dashed lines). As with the lip seal portion  68  of the rear seal  18  (see FIG. 4) the tip of the lip seal portion  86  ( 72  in FIG. 4B) may have a stabilizing bead to provide for some sweep variation in the hood undersurface that it seals against. 
     FIG. 7 illustrates an alternate embodiment of the hood seal  36  which includes the rigid plastic portion  80  and a softer plenum seal portion  84  but has a preferably round cross-section hollow bulb seal  82  to seal against the vehicle hood. This round hollow construction can accept even greater changes in surface contour of the opposing sealing surface. As with the aforementioned seal constructions, a co-extruded profile of talc-filled polypropylene and thermoplastic rubber is preferred in order that the opposing requirements (snap-fit with secure retention of the carrier portion and softer conforming surface of the seal portion) are embodied in a single-molding. 
     FIG. 8 describes an alternate locking mechanism for the hood seal  36  such that the retention forces against removal from the front edge  52  of the cowl grille panel  34  are increased. Similar to the cross-locking feature of the rear edge seal  18  to the windshield shown in FIG. 4A, this locking mechanism includes complementary features formed in the carrier portion  80  of the hood seal  36  and the front edge  52  of the cowl grille panel  34 , as shown in the circle indicated by arrow C as  110  and  112  respectively, to dielock the seal  36  onto the cowl grille panel  34 . This creates a cross-locking mechanism at  110 ,  112  vs.  114  to provide secure attachment for the seal on the grille panel front edge and is applicable to any of the embodiments of the present invention. 
     As shown in FIG. 9, another alternate embodiment of the hood seal  36  uses the rigidity of the carrier portion  80  to snap-fit over both the front edge  52  of the cowl grille panel  34  and the front edge  102  of the plenum tub  100  to provide a seal for the interface of the cowl grille panel  34  and the tub  100  without requiring the soft internal seal  90  shown in FIG.  5 . This provides an even less expensive and simpler sealing option. As with the hood seal  36  embodiment shown in FIG. 8, a cross-locking feature may be included at  114  and  110  (see FIG. 10) to securely locate and retain the hood seal  36  on the front edge of the cowl grille panel  34  and plenum  100 . 
     It should also be apparent from the above written description and drawings that the invention provides a self-contained, easily assembled cowl assembly for a vehicle adaptable to a wide variety of windshield, hood and plenum configurations for sealing a cowl grille panel to prevent noise, air and water leakage. The cowl assembly can be a filler piece for closing the space between the windshield, hood and fenders of a vehicle. It may also be part of the HVAC system of the vehicle by including inlet opening  38  for the passage of air to the HVAC unit. The cowl assembly of the present invention includes seals for the front and rear edges of the cowl grille panel which have a carrier portion configured to snap in place and be securely retained, and a softer conformable sealing portion which can conform tightly to an opposing surface, such as a windshield, a closed hood or an air plenum. Of particular note, is that no additional attachment mechanism such as mechanical fasteners or double-backed adhesive tape are required with the seals of the present invention. 
     The specific features of any single embodiment shown in the appending FIGS. are applicable to any and all of the embodiments shown. 
     The description and drawings illustratively set forth the presently preferred invention embodiment. We intend the description and drawings to describe this embodiment and not to limit the scope of the invention. Obviously, it is possible to modify these embodiments while remaining within the scope of the following claims. Therefore, within the scope of the claims one may practice the invention otherwise than as the description and drawings specifically show and describe.