Abstract:
An exhaust treatment device includes an inner shell spaced apart from an outer shell by a first gap. An inlet assembly includes a first inner cap and a first outer cap spaced apart by a second gap. An outlet assembly includes a second inner cap and a second outer cap spaced apart from each other by a third gap. A substrate is located within the inner shell. An insulating mat is positioned between the substrate and the inner shell and includes a reduced diameter portion compressing the insulating mat between the inner shall and the substrate. Insulation material fills the first, second and third gaps that are in communication with each other.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/274,818 filed on May 12, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 13/268,124, filed Oct. 7, 2011 (now U.S. Pat. No. 8,721,977, issued May 13, 2014). The entire disclosure of each of the above applications is incorporated herein by reference. 
     
    
     FIELD  
       [0002]    The present disclosure relates to an exhaust treatment device for reducing undesirable emissions from an internal combustion engine and, in particular, to a robust, integrated mounting system for supporting the exhaust treatment device on a vehicle. 
       BACKGROUND  
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Exhaust gas treatment devices such as catalytic converters, diesel oxidation catalysts, diesel particulate filters, and the like, may be employed in various applications to treat exhaust gasses emitted from internal combustion engines. Many of the exhaust gas treatment devices include relatively heavy components such as a ceramic substrate or a catalyst bed for treating the exhaust. The system for coupling the exhaust treatment device to the vehicle must withstand a wide range of external inputs such as when a vehicle wheel enters and exits a pothole in the road. 
         [0005]    Typical exhaust treatment devices are fixed to the vehicle underbody or frame with a number of welded brackets or straps. While these arrangements may have sufficiently supported the exhaust treatment device in the past, the cost and complexity of individually welding support brackets to the exhaust treatment device is undesirable. Depending on the number of brackets used and their location, stress concentrations may be introduced that may negatively affect the useful life of the exhaust treatment device. In addition, the use of clamps may introduce additional challenges in mounting to assure the proper orientation of the exhaust treatment device and the clamp in order to clear other vehicular components. 
         [0006]    One known exhaust treatment device includes an inlet end formed as a casting that is subsequently coupled to a sheet metal housing. The casting includes a mounting provision for the exhaust treatment device. Unfortunately, as the entire inlet assembly is formed from a cast component, heat is transferred readily from the interior of the exhaust treatment device to an exterior surface of the cast inlet assembly. Most end users and Original Equipment Manufacturers prefer an insulated arrangement where the external temperature of the treatment device remains below a predetermined maximum temperature. Furthermore, the casting is relatively large, heavy and costly. Accordingly, it may be beneficial to provide an improved exhaust treatment device including a cost effective integral mounting system having sufficient thermal shielding. 
       SUMMARY  
       [0007]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0008]    An exhaust treatment device includes an inlet tube having an end in communication with a cavity within a housing. A substrate for treating engine exhaust is positioned within the housing. A metal mounting member includes a mounting provision. A retaining plate is engaged with the metal mounting member and fixed to the housing to retain the mounting member between the housing and the retaining plate. 
         [0009]    An exhaust treatment device includes an insulation material positioned between an inner shell and an outer shell. An inlet tube has an end in communication with a cavity defined by the inner shell. A substrate for treating engine exhaust is positioned within the inner shell. A metal mounting ring is positioned between the inner and outer shells and includes a mounting provision for receipt of a fastener. 
         [0010]    An exhaust treatment device includes an inner shell, an outer shell and an insulation material positioned therebetween. An inlet tube includes an end in communication with a cavity defined by the inner shell. A substrate for treating engine exhaust is positioned within the inner shell. A metal mounting member includes a mounting provision. A cover plate engages the mounting member and is fixed to the outer shell to retain the mounting member between the outer shell and the cover plate. 
         [0011]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS  
         [0012]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0013]      FIG. 1  is a perspective view of an exemplary exhaust treatment device with an integral mount; 
           [0014]      FIG. 2  is a cross-sectional view taken through the exhaust treatment device depicted in  FIG. 1 ; 
           [0015]      FIG. 3  is a perspective view of a cast mounting ring; 
           [0016]      FIG. 4  is a cross-sectional view taken through the cast mounting ring depicted in  FIG. 3 ; 
           [0017]      FIG. 5  is a perspective view of an alternate exhaust treatment device; 
           [0018]      FIG. 6  is a cross-sectional view taken through the exhaust treatment device depicted in  FIG. 5 ; 
           [0019]      FIG. 7  is a cross-sectional view of an alternate exhaust treatment device; 
           [0020]      FIG. 8  is a partial end view of another alternate exhaust treatment device; 
           [0021]      FIG. 9  is a fragmentary cross-sectional of another exhaust treatment device; 
           [0022]      FIG. 10  is a fragmentary cross-sectional of another exhaust treatment device; 
           [0023]      FIG. 11  is a fragmentary cross-sectional of another exhaust treatment device; and 
           [0024]      FIG. 12  is a fragmentary cross-sectional of the exhaust treatment device depicted in  FIG. 11 . 
       
    
    
       [0025]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION  
       [0026]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0027]      FIGS. 1-4  depict an exemplary exhaust treatment device identified at reference numeral  10 . Exhaust treatment device  10  includes a first substrate  12  positioned upstream of a second substrate  14  within a housing  15 . First substrate  12  may be a diesel oxidation catalyst or a selective catalytic reduction device, while second substrate  14  may be a diesel particulate filter or a slip catalyst. Other exhaust treatment elements may be used in lieu of first substrate  12  and second substrate  14 . Furthermore, the present disclosure relates to an exhaust treatment device that includes one or more substrates within housing  15 . The two substrate arrangements depicted in the Figures is merely for illustration purposes. 
         [0028]    Housing  15  includes an inner shell  16  and an outer shell  17  surrounding inner shell  16 . Inner shell  16  includes several metal stampings coupled to one another. For example, inner shell  16  includes an inner tube  18  in receipt of first substrate  12  and second substrate  14 . The substrates  12 ,  14  are retained within inner tube  18  using a stuffing or sizing process for compressing a first mat  28  between first substrate  12  and inner tube  18 , as well as compressing a second mat  30  between second substrate  14  and inner tube  18 . Outer shell  17  also includes several interconnected stampings such as an outer tube  34  circumscribing inner tube  18 . An insulation material  36  surrounds inner tube  18  and is positioned between outer tube  34  and inner tube  18 . 
         [0029]    An inlet assembly  37  is fixed to outer tube  34  and inner tube  18 . Inlet assembly  37  includes a ring cover plate  38  having a flange  40  fixed to a first end cap  44 . An inner inlet  41  includes a lip  43  fixed to inner tube  18 . Inner inlet  41  forms a portion of inner shell  16  while end cap  44  forms a portion of outer shell  17 . 
         [0030]    A mounting ring  54  is positioned between first end cap  44  and ring cover plate  38 . Mounting ring  54  may be cast from a ductile iron having a high content of silicon and molybdenum as a one-piece monolithic component. This material provides excellent structural physical properties and may withstand the high temperature environment of the exhaust treatment device. The mounting ring may alternatively be formed using processes such as forging, stamping, or machining. Metallic materials other than those listed are also contemplated. 
         [0031]    Mounting ring  54  includes a generally cup-shaped hollow cross section defined by an inner wall  60  and an outer wall  62  interconnected by an end wall  64 . A plurality of solid mounting bosses  66  are circumferentially spaced apart from one another. Each boss  66  includes a threaded aperture  68  for receipt of a fastener (not shown) to mount exhaust treatment device  10  to the vehicle. To define a robust structural mount for exhaust treatment device  10 , an inner surface  70  of first end cap  44  is shaped as a pocket complementing an external surface  72  of mounting ring  54 . A plurality of apertures  76  extend through first end cap  44  in alignment with threaded apertures  68 . It should be appreciated that mounting ring  54  need not include the cup-shaped portions and may be shaped to have a more consistent solid cross-section. 
         [0032]    To assemble exhaust treatment device  10 , mounting ring  54  is placed into engagement with inner surface  70 . Ring cover plate  38  is positioned to engage mounting ring  54 . Flange  40  is welded to first end cap  44  to retain mounting ring  54  at a desired location and provide a structural interconnection between the casting and the remaining stamped steel components. First end cap  44  is also welded to mounting ring  54 . An insulation material  77  is trapped between ring cover plate  38  and inner inlet  41 . 
         [0033]    Ring cover plate  38  includes at least one boss  48  engaging a like boss or plurality of bosses  50  formed on inner inlet  41 . First end cap  44  also includes a boss or set of bosses  78  positioned in engagement with the boss or bosses  48  of ring cover plate  38 . Each set of bosses are welded together to fix first end cap  44 , ring cover plate  38  and inner inlet  41  to each other. Each weld joins three adjacent sheet steel portions. First end cap  44  includes a flange  46  that is fixed to outer tube  34  after the completion of inlet assembly  37 . A thermal shield  80  may optionally be fixed to an exterior surface of first end cap  44  to cover bosses  78  because these areas are devoid of insulation  77 . 
         [0034]    An inlet pipe assembly  82  includes a pipe  84  fixed to a shield  86 . An insulation material  88  is positioned between pipe  84  and shield  86 . Pipe  84  includes a first end  90  extending through both outer tube  34  and inner tube  18  in communication with a cavity  92  formed upstream of first substrate  12 . An inlet  94  is formed at the second opposite end of inlet pipe assembly  82  for receipt of exhaust from the internal combustion engine. 
         [0035]    A flow distribution plate  96  is fixed to inner inlet  41  at a position downstream from first end  90  of pipe  84 . Flow distribution plate  96  includes a plurality of spaced apart apertures  98  having different sizes to induce a substantially uniform exhaust gas flow through first substrate  12 . 
         [0036]    An outlet assembly  100  may be constructed using some of the same or at least very similar components used to manufacture inlet assembly  37 . For example, outlet assembly  100  includes a second end cap  44   a,  a ring cover plate  38   a,  an insulation material  77   a,  an inner outlet  41   a,  a pipe  84   a,  a shield  86   a,  insulation  88   a  and an outlet  94   a.  Other features of outlet assembly  100  are substantially similar to the features of the components forming inlet assembly  37 . As such, these elements will be identified with a lower “a” suffix. 
         [0037]    The interconnection of components to form outer assembly  100  is substantially the same as inlet assembly  37  with the exception that mounting ring  54  is not present within outlet assembly  100  depicted in the Figures. It should be appreciated, however, that should mounting flexibility be required, outlet assembly  100  may include a mounting ring substantially similar to mounting ring  54 . In yet another arrangement, inlet assembly  37  may be constructed without mounting ring  54  and outlet assembly  100  may include a mounting ring sandwiched between second end cap  44   a  and ring cover plate  38   a.    
         [0038]      FIG. 5  depicts an alternate exhaust treatment device identified at reference numeral  110 . Exhaust treatment device  110  is substantially the same as exhaust treatment device  10  with the exception that outlet assembly  100  has been replaced with an outlet assembly  114 . Outlet assembly  114  includes an inner cone  116  fixed to inner tube  18  and an outer cone  118  fixed to outer tube  34 . An insulation material  120  is positioned between inner cone  116  and outer cone  118 . A tube  124  extends through apertures formed in both outer cone  118  and inner cone  116  to place a first end  126  of tube  124  in communication with a cavity  128 . Tube  124  includes an outlet  130  to allow treated exhaust to escape exhaust treatment device  110 . 
         [0039]    Exhaust treatment device  110  provides an alternate plumbing arrangement from device  10 . Pipe  84  transversely intersects an axis aligned with a direction of exhaust flow through substrates  12 ,  14 . Tube  124  provides an outlet coaxially aligned with this flow axis. This contrasts with the plumbing arrangement defined by exhaust treatment device  10  where both the inlet  94  and the outlet  94   a  extend at right angles to a direction of exhaust flow through substrates  12 ,  14 . One skilled in the art will appreciate that other geometrical arrangements of the inlet, outlet and exhaust flow path are contemplated as being within the scope of the present disclosure. 
         [0040]      FIG. 7  depicts an alternate exhaust treatment device identified at reference numeral  200 . Exhaust treatment device  200  is substantially the same as exhaust treatment device  110  with the exception that inlet assembly  37  is replaced with an inlet assembly  202 . Inlet assembly  202  includes an inner inlet  204  fixed to inner tube  18  to form a portion of inner shell  16 . An end cap  206  is a cup-shaped stamping surrounding inner inlet  204  and includes an end  207  fixed to outer tube  34  to form a portion of outer shell  17 . Insulation  208  is positioned between inner inlet  204  and end cap  206 . A mounting member  210  is sandwiched between an inner surface  212  of end cap  206  and a retaining plate  214 . Retaining plate  214  is fixed to end cap  206 . An inlet pipe assembly  220  includes a pipe  222  fixed to a shield  224 . An insulation material  226  is positioned between pipe  222  and shield  224 . Pipe  222  includes a first end  228  extending through end cap  206 , retaining plate  214 , and inner inlet  204  to be in communication with cavity  94  upstream of first substrate  12 . Shield  224 , retaining plate  214  and inner inlet  204  are fixed to pipe  222 . Pipe  222  extends through mounting member  210 . 
         [0041]    Another alternate exhaust treatment device is identified at reference numeral  250  and depicted in  FIG. 8 . Exhaust treatment device  250  is substantially similar to each of the embodiments previously described with at least one exception that the cross-sectional shape of the device is not necessarily a circle or some other regular polygon. Exhaust treatment device  250  also includes a first mounting member  252  spaced apart from a second mounting member  254  in lieu of the one-piece mounting member previously described. It should be appreciated that any number of spaced apart mounting members may be incorporated without departing from the scope of the present disclosure. The individual mounting members are contemplated as being coupled to the exhaust treatment device as previously described. For example, first mounting member  252  and second mounting member  254  may be positioned within an end cap not depicted in  FIG. 8 . The mounting members  252 ,  254  may be subsequently trapped between a retaining plate and the end cap. It is also within the scope of the present disclosure to use multiple spaced apart mounting members in the exhaust treatment devices subsequently introduced in this document. 
         [0042]      FIG. 9  depicts a portion of another alternate exhaust treatment device identified at reference numeral  300 . Exhaust treatment device  300  is substantially similar to the exhaust treatment devices previously described with at least one exception that an end cap  302  and a mounting member  316  may be fixed to a previously assembled exhaust treatment device. End cap  302  may be fixed directly to a flange  304  of an outer end plate  306  instead of being directly coupled to outer tube  34 . An inner end plate  308  may be fixed to inner tube  18 . Inner end plate  308  may be shaped as shown in  FIG. 9  or may be elongated and conically shaped as previously described and identified as an inner inlet or an inner outlet. An insulation material  310  is positioned between inner end plate  308  and outer end plate  306 . In the arrangement shown in  FIG. 9 , flange  304  of outer end plate  306  is fixed to an outer surface  312  of outer tube  34 . A portion of end cap  302  overlaps flange  304  and is fixed thereto. 
         [0043]    Mounting member  316  is trapped between end cap  302  and outer end plate  306 . It should be appreciated that in another configuration not shown in  FIG. 9 , flange  304  may engage an inner surface  318  of outer tube  34  while end cap  302  directly engages outer surface  312  of outer tube  34 . 
         [0044]    By arranging the components as depicted in  FIG. 9 , a simplified method of manufacture may result. More particularly, insulation  310  may be accurately compressed a desired amount by engaging outer end plate  306  with inner end plate  308  prior to fixing flange  304  to outer tube  34 . The assembly exhaust treatment device  300  may be substantially complete before handling and coupling mounting member  316  to device  300 . 
         [0045]    Once inner end plate  308  and outer end plate  306  have been fixed to inner tube  18  and outer tube  34 , mounting member  316  is positioned within a pocket formed in end cap  302 . End cap  302  is positioned to overlap flange  304  and engage outer end plate  306  at or near its center. At this location, each of the three stamped metal components, end cap  302 , outer end plate  306  and inner end plate  308  may be simultaneously welded together. Mounting member  316  may engage an outer surface  322  of outer end plate  306 . An outer perimeter of end cap  302  may also be welded to flange  304 . 
         [0046]      FIG. 10  shows another alternate exhaust treatment device identified by reference numeral  350 . Only a portion of the exhaust treatment device is shown in  FIG. 10  to illustrate the differences from the previously described devices. Exhaust treatment device  350  includes an inner shell  352  including an inner tube  354  and an inner end plate  356 . An outer shell  360  includes an outer tube  362  surrounding inner tube  354  and an outer end plate  364 . An insulation  366  is positioned between inner tube  354  and outer tube  362 , as well as between inner end plate  356  and outer end plate  364 . 
         [0047]    A mounting member  368  is positioned between inner end plate  356  and outer end plate  364 . In one arrangement, a pocket  370  is formed in outer end plate  364  for receipt of mounting member  368 . As previously described, mounting member  368  may be constructed as a one-piece monolithic member or, alternatively, may include more than one spaced apart mounting member. In the configuration depicted in  FIG. 10 , an inner surface  374  of mounting member  368  is positioned in engagement with an outer surface  380  of insulation  366 . It should be appreciated that insulation  366  is compressible and a biasing load made be applied on mounting member  368  based on the position of outer end plate  364  and mounting member  368  prior to fixing outer end plate  364  to outer tube  362 . A stud  384  is fixed to mounting member  368  and extends through an aperture  386  of outer end plate  364 . Stud  384  includes an external thread useful for mounting exhaust treatment device  350  to a support structure. Externally threaded stud  384  is merely an example of a mounting provision that can be provided by mounting member  368 . It is also contemplated that mounting member  368  may include an internally extending blind threaded bore. Other mounting provisions including differently shaped fasteners are contemplated as being within the scope of the present disclosure. These fasteners may extend outwardly beyond an outer surface of outer end plate  364  or may be internally located within mounting member  368  and accessible via aperture  386 . The alternate mounting provisions may be part of any of the mounting members or mounting rings described in this paper. 
         [0048]      FIGS. 11 and 12  depict an exhaust treatment device  400  equipped with an alternate or supplementary mount  402 . Mount  402  includes a mounting member  404  positioned in contact with an outer surface  406  of outer tube  34 . A retaining plate  410  includes an inner surface  412  shaped as a pocket complementing an outer profile of mounting member  404 . Retaining plate  410  is fixed to outer tube  34  at flanges  416 ,  418 . Mounting member  404  or retaining plate  410  need only extend along a portion of the circumference of outer tube  34  as depicted in  FIG. 12 . To save cost and weight, mounting member  404  and retaining plate  410  circumferentially extend less than 180 degrees. An aperture  422  extends through retaining plate  410  to allow access to a threaded blind bore  424 . Alternatively, a stud or other fastener may be fixed to mounting member  404  and extend through aperture  422 . 
         [0049]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. For example, the mounting member and retaining plate interactions previously described could be utilized on an exhaust treatment device having a single wall in lieu of the inner and outer shell construction previously described. Other features may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.