Patent Publication Number: US-7913489-B2

Title: Device for lowering tail pipe exhaust temperature

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of U.S. Provisional Application No. 60/858,762, filed Nov. 14, 2006, which is hereby incorporated by reference. 
    
    
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     MICROFICHE/COPYRIGHT REFERENCE 
     Not Applicable. 
     FIELD OF THE INVENTION 
     The disclosure relates generally to vehicle exhaust treatment devices and more specifically to an exhaust pipe component or attachment for reducing exhaust temperature and eliminating hot spots in the exhaust flow exiting a vehicle. 
     BACKGROUND OF THE INVENTION 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Conventional tail pipe temperatures, especially for diesel particulate filter applications show peaks as high as 650° C. with so-called “hot spots” in the axial center of the flow exiting the tail pipe. Such exhaust gas temperatures can potentially ignite flammable materials, such as dry grass along a roadside. Hence, there is seen to be a need in the art for a component device for an exhaust pipe, such as a tail pipe of a vehicle, for lowering the exhaust temperatures while avoiding isolated hot spots in the center of the exhaust flow emanating from the vehicle. 
     SUMMARY OF THE INVENTION 
     An component for a vehicular exhaust pipe includes an upstream venturi forming portion for creating at least a partial vacuum interior to the component. A downstream diverter housing portion of the component has an inlet coupled to an outlet of the venturi portion. A gap or inlet is formed between the venturi forming portion and the diverter housing portion. The diverter housing portion includes a diverter element positioned adjacent an output of the diverter housing the diverter housing. The partial vacuum in the component device causes colder environmental ambient air to enter the diverter housing portion through the gap or inlet. The diverter also creates a mixture of the hot exhaust flow with the colder environmental air, resulting in a lower temperature of the exhaust gas exiting the component and substantial elimination of centrally disposed exhaust hot spots. 
     Other objects, features, and advantages of the invention will become apparent from a review of the entire specification, including the appended claims and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the disclosure will become apparent from a reading of a detailed description, taken in conjunction with the drawing, in which: 
         FIG. 1  is a side cross-sectional view of a combination venturi/diverter exhaust pipe component arranged in accordance with the principles of the invention; 
         FIG. 2  is a side perspective view of the component of  FIG. 1 ; 
         FIG. 3  is an end perspective view at the diverter end of the component of  FIG. 1 ; and 
         FIG. 4  is an end perspective view at the venturi forming member inlet end of the component of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, applications, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     With reference to  FIGS. 1-4 , component  100  is intended preferably for coupling to a tail pipe of a vehicular exhaust system, and is comprised of an upstream portion  102  and a downstream portion  104 . 
     Upstream portion  102  includes a venturi forming element or nozzle  106  and an upstream portion of the diverter housing  108  which tapers from an inlet end to point  124 . Venturi forming element  106  is coupled to the upstream portion  102  of housing  108  by a plurality of legs  112 , two being shown in  FIG. 1  as  112   a  and  112   b . Diverter housing portion  108  and venturi forming portion  106  are attached to opposite ends of legs  112  by, for example, welding. 
     Venturi forming element  106  narrows radially at  110  internally of diverter housing  108  to create a jet generating higher exhaust flow velocities, resulting in a suction effect, which, in turn, creates at least a partial vacuum inside component  100 . The partial vacuum draws colder environmental ambient air into an annular inlet  115  formed between the outer wall of the element  106  and an inlet end  117  of the diverter housing portion  108 . 
     Diverter  114 , in a preferred form, comprises a conical element  114  having an apex  118  facing the oncoming exhaust stream and a base  116  facing the output  120  of component  100 . 
     Diverter  114  is mounted centrally of the wall of substantially cylindrical diverter housing portion  108  by a plurality of mounting struts or legs  122  (four shown in the drawing— 122   a, b, c  and  d ). Struts  122   a - d  are attached, for example, by welding, at first inner ends to diverter  114  and at second outer ends to an interior surface of the cylindrical wall of housing  108 . 
     Nozzle  106  is adapted to be coupled at its input  118  to an end of an exhaust tail pipe (not shown), for example, by a radial clamp  202  whose ends accept a bolt  204  engaged by a nut  206 . 
     In operation, hot exhaust gas enters input  118  of venturi forming element  106  from the vehicle&#39;s tail pipe to form a jet at restriction  110 . The resultant partial vacuum in housing  108  pulls in cooler ambient air from outside the exhaust system into inlet  115  to mix with the hot exhaust gas moving toward diverter  114  and outlet  120 . Diverter  114  forces the mixture radially outwardly toward the substantially cylindrical wall of housing  108 , thereby eliminating hot spots along the central axis of the exhaust flow. The ambient air/exhaust mixture also results in a lower temperature exhaust stream exiting component  100 . Additionally, the exhaust gases exiting the outlet  120  are mixed and further diluted outside of the device by pulling ambient air into a low pressure area (vena contracta) formed downstream of the diverter  114  and the outlet  120 . 
     The invention has been described with reference to a preferred embodiment which has been set forth for the sake of example only. The scope and spirit of the invention will be derived from appropriate construction of the appended claims.