Abstract:
A vehicle air intake assembly is disclosed. The assembly includes a housing, a conical filter, and optionally may also include an inlet cowl. The housing and filter decrease in diameter from an inlet or distal end toward a proximal or outlet end. The shape of the housing guides the air into a smaller cross-sectional area and induces a Venturi effect on the airflow passing through the housing and filter. The housing decouples the filter from an engine inlet and the proximal or outlet end of the housing is sized so as to attach to the engine inlet and provide a smooth transition for the air leaving the housing and entering the engine inlet.

Description:
FIELD OF THE INVENTION 
       [0001]    The field of the present invention relates generally to an air intake housing for vehicles. 
       BACKGROUND 
       [0002]    Motor vehicles are equipped with an air filter system that filters air destined for the engine. Conventional air filter systems use a cuboidal filter enclosed by a cuboidal housing. This type of air filter cause the air to transition from a rectangular filter housing outlet to a cylindrical pipe inlet. Such an abrupt transition in geometrical shape causes the airflow to be turbulent, and hence causes engine “choking,” particularly at high RPM. 
         [0003]    More recent, aftermarket intake systems use a conical filter in place of the conventional rectangular filter. The conical filter in these aftermarket systems is directly connected to the inlet pipe of the engine and is oriented such that the smaller diameter of the conical filter is upstream and the larger diameter is downstream with respect to airflow into the engine. Moreover, the larger diameter of the conical filters conventionally has a neck attached to the filter to allow the filter to be connected to piping, such as engine air inlet piping. 
         [0004]    The conventional air intake systems, whether cuboidal or conical, do not properly shape the airflow directed into the engine or carburetor inlet. For example, in conical filters positioned with their larger diameter adjacent the engine inlet, airflow must negotiate through an abrupt change in geometrical shape from the filter material through the smaller diameter neck that leads to the engine inlet. This causes turbulent airflow in the filter and inhibits the airflow from increasing in velocity as the air traverses the filter and enters the engine inlet. These and other deficiencies exist. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  depicts a perspective view of an exemplary air intake housing assembly according to an exemplary embodiment; 
           [0006]      FIG. 2  depicts a side view of the exemplary air intake housing assembly of  FIG. 1 , according to an exemplary embodiment; 
           [0007]      FIGS. 3-3A  depict a side view of an assembled exemplary air intake housing assembly and cross-section thereof, according to an exemplary embodiment; 
           [0008]      FIG. 4  depicts a perspective view of an exemplary air intake housing assembly according to another exemplary embodiment; 
           [0009]      FIG. 5  depicts a side view of the exemplary air intake housing assembly of  FIG. 4 , according to an exemplary embodiment; 
           [0010]      FIGS. 6-6A  depict a side view of an assembled exemplary air intake housing assembly and cross-section thereof, according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    Reference will be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. It should be appreciated that the same reference numbers will be used throughout the drawings to refer to the same or like parts. The following description is intended to convey a thorough understanding of the embodiments described by providing a number of specific embodiments. It should be appreciated that the following detailed descriptions are exemplary and explanatory only and are not restrictive. As used herein, any term in the singular may be interpreted to be in the plural, and alternatively, any term in the plural may be interpreted to be in the singular. 
         [0012]    Exemplary embodiments of the present invention pertain to a filter housing that encloses a conical filter. The conical filter is reversed so that the larger diameter is upstream with respect to the smaller diameter and the engine inlet. The filter housing decouples the filter from the engine inlet such that the filter, or a neck attached to the filter, is not mounted directly onto the inlet tubing of the engine. In exemplary embodiments, the larger diameter ends of the conical filter and housing are open to the surrounding environment such that air enters the housing and conical filter from the surrounding environment at the larger diameter side and is gradually led to the smaller diameter side of the conical filter and housing. Like the filter, the housing that encapsulates the filter gradually reduces in diameter from a larger diameter to a smaller diameter. In exemplary embodiments, the small-diameter side dimensionally matches the inlet tubing diameter of the engine inlet so as to enable attachment between the housing and engine inlet. The funnel-shaped housing invokes the Venturi effect where the smooth reduction in cross-sectional area along the length of the housing causes the airflow to increase in velocity as the air passes through the housing. Moreover, the housing shields the filter and airflow from heat emanating from the engine bay, thereby enabling cool, atmospheric air to enter the engine. 
         [0013]    Referring to  FIG. 1 , an exploded view of an exemplary Venturi air intake housing assembly is shown. The exemplary housing assembly comprises a housing  110 , a conical filter  120 , and optionally may further comprise an inlet cowl  130 . The housing  110  is shaped such that there is a smooth reduction in cross-sectional area along the substantially entire length of housing  110 . 
         [0014]    Referring to  FIG. 2 , an exploded side view of the exemplary Venturi air intake housing assembly  101  of  FIG. 1  is shown. Housing  110  may be connected directly to engine inlet  100  with bolts and/or ring clamps, for example. The engine inlet  100  may refer to the inlet tubing of the engine through which filtered, ambient air passes, or may refer to an airflow sensor tube. The Venturi air intake housing assembly  101  may be retrofitted onto the engine inlet  100  so as to replace a conventional cuboidal air intake system. 
         [0015]    Referring to  FIGS. 3-3A , a side view of an assembled exemplary air intake housing assembly  101  and cross-section thereof are shown. As shown, the diameter of the housing  110  decreases gradually from a distal portion to a proximal portion. “Distal” refers to the large diameter side of the housing  110  and is the portion farthest from the engine inlet  100 . “Proximal” refers to the small diameter side of the housing  110  and is the portion closest to the engine inlet  100 , and in some embodiments may be coupled directly to the engine inlet  100  ( FIG. 2 ). The distal end of the housing  110  may be positioned near a front of the vehicle, such as behind a grille or near a headlamp of the vehicle. More specifically, the distal opening of the housing  110  may be positioned such that air passes through a front of the vehicle and into the housing  110 . 
         [0016]    As shown in  FIGS. 1-6A , the diameter of the housing  110 ,  210  may decrease over substantially the entire length of the housing  110 ,  210 . This gradual reduction in diameter allows the airflow to be substantially laminar while traveling through the housing. In other words, the motion of the air is orderly with the air particles moving substantially in straight lines parallel to the walls of the housing  110 ,  210  with little lateral mixing or cross-currents perpendicular to the walls of the housing  110 ,  210 . 
         [0017]    Conical filter  120  may be a double cone or single cone conical filter, for example.  FIGS. 1-3A  show a double cone conical filter  120  where one outer cone encapsulates an inner cone. As shown in  FIG. 3A , an outer diameter of the filter  120  may correspond to, or be substantially equal to, an inner diameter of the housing  110  at a distal end of the housing  110  and filter  120 . Moving proximally, as the diameter of the filter  120  decreases, so too does the diameter of the housing  110 , though not necessarily by the same degree. Conical filter  120  may be attached to housing  110  by various means, including, for example, nuts and bolts or screws. Preferably the filter  120  is not fixedly attached to housing  110  (e.g., by glue) so as to enable removal of filter  120  after a period of time, such as when filter  120  is dirty. 
         [0018]    Inlet cowl  130  may optionally be secured to a distal end of housing  110  and filter  120  by various means, including, for example, nuts and bolts or screws. The purpose of the optional inlet cowl  130  is to further guide airflow into filter  120  and housing  110 . As shown in  FIG. 3A , an inner diameter of the inlet cowl  130  at a proximal end thereof may correspond to, or be substantially equal to, an inner diameter of the filter  120  at a distal end thereof. 
         [0019]    As shown in  FIGS. 2 and 3A , an outer diameter of the conical filter decreases from a distal to a proximal end thereof. The proximal end of the filter  120  is decoupled from the engine inlet  100  because of housing  110 . Filter  120  partially shapes the airflow into a smaller cross-sectional area as air enters the filter  120  at the distal end and traverses toward the proximal end of filter  120 . Air that traverses the porous wall of the filter  120  is further shaped by the housing  110  into a smaller cross-sectional area. Thus, at each cross-section of the filter  120  and housing  110 , air is being channeled into a smaller cross-sectional area by both the filter  120  and housing  110 . This is a substantial departure and improvement over conventional filter and housing combinations where one or both of the filter and housing did not channel airflow therethrough into a smaller cross-sectional area due to their geometrical shape and orientation with respect to the engine inlet. 
         [0020]    The smooth reduction in cross-sectional area of the disclosed air filter housing assembly allows the airflow to remain laminar and therefore maximizes the aerodynamic efficiency of the system, which results in increased power output of the engine. The funnel-like shape of the housing  110  in combination with filter  120  invokes the Venturi effect. In accord with the principles of conservation of mass and mechanical energy, a fluid&#39;s velocity must increase as it passes through a constriction while its static pressure must decrease. Thus any gain in kinetic energy a fluid may accrue because of its increased velocity through a constriction is balanced by a drop in pressure. As air travels through the housing  110 , the air passes through increasingly smaller diametrical cross-sections of the housing  110 . Therefore, the airflow velocity increases and there is a drop in pressure at the proximal end of housing  110 . This drop in pressure at proximal end of housing  110  effectively sucks additional air through the housing  110  and ultimately into the engine&#39;s air inlet  100 . 
         [0021]    Volumetric flow rate, Q, may be represented by Q=v 1 A 1 =v 2 A 2  , where v represents velocity and A represents cross-sectional area at points 1 and 2. Pressures (P 1  and P 2 ) at points 1 and 2 are represented by P 1 −P 2 =ρ/2(v 2   2 −v 1   2 ). Using these equations, the volumetric flow rate, pressures, and/or air velocities may be calculated at different points, such as at the distal and proximal ends of housing  110 / 210 . Further, cross-sectional areas at the distal and proximal ends of housing  110 / 210  can be optimized so as to improve flow of ambient air into the engine. 
         [0022]    The housing  110  also serves to shield the filter  120  and airflow from engine heat. Thus, the airflow is able to remain as close to ambient air temperature as possible (i.e., ambient with respect to the vehicle). The housing  110  may be made of carbon fiber, i.e., a polymer reinforced with carbon fibers. Alternatively, housing  110  may be made of plastic. 
         [0023]    Tests on a dynamometer have shown an increase in power and torque on high performance vehicles that have the air intake housing assembly  101  installed. For example, tests on a BMW E60 M5 shown a gain of approximately 16 horsepower when using the air intake housing assembly  101 , compared to a conventional cuboidal air intake housing system. Similarly, on a BMW M3, an increase of 10-15 horsepower was measured when using the air intake housing assembly  101  disclosed herein. Further, on both of these vehicles, there was a significant improvement in throttle response, even at low RPM. The air intake housing assemblies  101 ,  201  disclosed herein also substantially improve the sound of the engine by naturally amplifying the engine&#39;s sound. Conventional cuboidal air filter systems tended to muffle the engine sound. 
         [0024]      FIGS. 4-6A  show an alternative embodiment of an air intake housing assembly  201 . Air intake housing assembly  201  may comprise a housing  210 , conical filter  220 , and optionally an inlet cowl  230 . Contrary to assembly  101 , assembly  201  may be shorter in length, smaller in diameter, and filter  220  may be a single cone conical filter as opposed to a double cone conical filter. Further, as shown in  FIG. 6A , filter  220  may be inset more towards a proximal end of housing  210 , and inlet cowl  230  may not protrude from a distal end of housing  210 , but may protrude into housing  210  so as to guide airflow directly into filter  220 . The cone filter used in this configuration may have a neck on the larger diameter side to which the inlet cowl  230  is secured by clamp or nuts and bolts, for example. In such a case, the inlet cowl  230  protrudes inside the neck of the filter, which allows a clamp to be used on the outside of the neck to secure the filter  220  to the inlet cowl  230 . Nevertheless, similar to air intake assembly  101 , a cross-sectional diameter of the housing  210  and filter  220  both decrease from a distal end to a proximal end of the assembly  201 . And a proximal end of housing  210  is sized so as to correspond to a size of an engine inlet  100 . Other similarities between assemblies  101  and  201  may be readily apparent to one of ordinary skill in the art. For example, the distal end of the housing  210  in assembly  201  may be positioned near a front of the vehicle, such as behind a grille or near a headlamp of the vehicle. More specifically, the distal opening of the housing  210  may be positioned such that air passes through a front of the vehicle and into the housing  210 . 
         [0025]    The dimensions of the air intake assemblies  101  and  201  may vary depending on the vehicle to which the assembly is to be connected and the relative degree of airflow velocity and pressure differential desired with respect to the distal and proximal ends of the housing  110 / 210 . Exemplary outer diameters of housing  110  that provided beneficial results were 198 mm and 83 mm at the distal and proximal ends, respectively, and a length of 223 mm. Exemplary outer diameters of housing  210  include 174 mm and 80 mm at the distal and proximal ends, respectively, and a length of 190 mm. 
         [0026]    It will be readily understood by those persons skilled in the art that the present invention is susceptible to broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and foregoing description thereof, without departing from the substance or scope of the invention. 
         [0027]    While the foregoing illustrates and describes exemplary embodiments of this invention, it is to be understood that the invention is not limited to the construction disclosed herein. The invention can be embodied in other specific forms without departing from the spirit or essential attributes.