Abstract:
A serviceable exhaust aftertreatment device and configured cylindrical bodies for coupling include a raised annular rib or bead structure providing low profile mounting and ease of assembly.

Description:
BACKGROUND AND SUMMARY 
     The invention relates to serviceable exhaust aftertreatment devices and to cylindrical bodies configured for coupling. 
     The invention arose during continuing development efforts relating to serviceable exhaust aftertreatment devices, such as diesel particulate filters (DPF), catalytic elements, mufflers, and the like, including various combinations thereof. An exhaust aftertreatment device requires service at predetermined intervals. In such device, one or more central sections are attached to an inlet section and an outlet section, for flow distribution and mechanical construction, typically application dependent. To service a central section, the inlet section and the outlet section must be removed. Existing serviceable exhaust aftertreatment devices require expensive clamps and sophisticated flanges for joining and sealing mating surfaces, such as 90° flanges. Servicing may include replacement with a new or different element, or may involve a re-usable element wherein soot, ash or contaminant build-up is cleaned from the removed element and then the now-cleaned re-usable element is re-installed. The element may include various types of emissions components. 
     Design requirements include: serviceability, as noted; structural integrity; leak prevention; cost effective manufacturability; and ease of assembly. A further requirement is low profile mountability. Typical designs in the prior art add 0.5 inch or more to the outer diameter of the device (typically having a diameter in the range of 7 inches to 13 inches), to accommodate the added radial height or dimension of a flange or clamp. This extra 0.5 inch is objectionable in various applications where only severely limited space is available. 
     The present invention addresses and solves the above noted needs in a particularly simple and effective manner. In one embodiment, the invention requires an increase in outer diameter in the range of 1 to 2% to accommodate the coupled bodies, as opposed to 4 to 7% in the prior art. In one particular embodiment, in an exhaust aftertreatment device having a main body outer diameter in the range of 7 to 13 inches, the present invention requires an increase in outer diameter of only 0.125 inch at the coupling of the bodies. In further aspects, the invention facilitates easy removal and replacement of a central section of the exhaust aftertreatment device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of an exhaust aftertreatment device in accordance with the invention. 
         FIG. 2  is an exploded perspective partial view of the device of  FIG. 1 . 
         FIG. 3  is a profiled sectional view of the sidewall construction of the exhaust aftertreatment device of  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1–3  show a serviceable exhaust aftertreatment device  10  for exhaust flowing as shown at arrows  12 ,  14  along an axial flowpath  16  from upstream at inlet pipe  18  to downstream at outlet pipe  20 . Device  10  includes an inlet cylindrical body  22  providing an inlet section, one or more central cylindrical bodies  24  providing a central section, and an outlet cylindrical body  26  providing an outlet section. The central section provides exhaust aftertreatment, for example as provided by a diesel particulate filter and/or a catalyst and/or a muffler and/or a combination thereof. Cylindrical bodies  22 ,  24 ,  26  are axially colinearly aligned along axis  16 . Cylindrical body  24  is axially between cylindrical bodies  22  and  26  and is removable therefrom, for servicing, to be described. Each of the cylindrical bodies has a main body outer profile of given outer diameter  28 . Cylindrical body  22  mates with cylindrical body  24  at junction  30 . Cylindrical body  24  mates with cylindrical body  26  at junction  32 . Each of the junctions has an outer profile of increased outer diameter  34 ,  FIGS. 1 ,  3 . The increase in outer diameter from 28 to 34 is less than 2%, and preferably as enabled in the present invention is in the range of 1 to 2%. Further particularly, in an exhaust aftertreatment device having a given outer diameter  28  in the range of 7 to 13 inches, the increase in outer diameter  34  is approximately 0.125 inch. 
     Cylindrical bodies  22  and  24  are mated and sealed to each other without a gasket therebetween. Cylindrical bodies  24  and  26  are mated and sealed to each other without a gasket therebetween. Cylindrical bodies  22  and  24  are mated and sealed to each other along an axially extending annulus  36 . Cylindrical bodies  24  and  26  are mated and sealed to each other along a second axially extending annulus  38 . Cylindrical bodies  22  and  24  have first and second structurally rigidizing annular beads  40  and  42 , respectively, at axially distally opposite upstream and downstream ends of annulus  36 . Cylindrical bodies  24  and  26  have third and fourth structurally rigidizing annular beads  44  and  46 , respectively, at axially distally opposite upstream and downstream ends of annulus  38 . Beads  40 ,  42 ,  44 ,  46  are provided by respective raised annular ribs providing the respective structural rigidizing beads. First and second beads or ribs  40  and  42  are axially nonoverlapped in assembled condition, and are axially spaced by annulus  36  therebetween in assembled condition. Beads or ribs  44  and  46  are axially nonoverlapped in assembled condition, and are axially spaced by annulus  38  therebetween in assembled condition. 
     Cylindrical body  22  has distally opposite upstream and downstream axial ends  48  and  50 . Cylindrical body  24  has distally opposite upstream and downstream axial ends  52  and  54 . Cylindrical body  26  has distally opposite upstream and downstream axial ends  56  and  58 . Downstream end  50  of cylindrical body  22  engages upstream end  52  of cylindrical body  24  in axial sliding telescoped relation. Downstream end  54  of cylindrical body  24  engages upstream end  56  of cylindrical body  26  in axial sliding telescoped relation. Exhaust aftertreatment device  10  is serviced by axially sliding cylindrical bodies  22  and  24  away from each other and axially sliding cylindrical bodies  24  and  26  away from each other. Central section  24  is then removed and replaced by a replacement exhaust aftertreatment section, which may be a new section, or may be the same section cleaned and re-used, and the cylindrical bodies are axially slid towards each other into the noted axial sliding telescoped engagement. 
     Downstream end  50  of cylindrical body  22  has the noted beaded construction provided by raised annular rib  40  of increased radial height  34 , and has an annular flange  60  extending axially downstream from rib  40 . Upstream end  52  of cylindrical body  24  has the noted beaded construction provided by raised annular rib  42  of increased radial height  34 , and has a second annular flange  62  extending axially upstream from rib  42 . Downstream end  54  of cylindrical body  24  has the noted beaded construction provided by third raised annular rib  44  of the noted increased radial height  34 , and has a third annular flange  64  extending axially downstream from rib  44 . Upstream end  56  of cylindrical body  26  has the noted beaded construction provided by fourth raised annular rib  46  of the noted increased radial height  34 , and has a fourth annular flange  66  extending axially upstream from rib  46 . First and second annular flanges  60  and  62  engage in axial sliding telescoped relation without overlap of first and second raised annular ribs  40  and  42 . Third and fourth annular flanges  64  and  66  engage in axial sliding telescoped relation without axial overlap of third and fourth annular ribs  44  and  46 . This permits servicing of exhaust aftertreatment device  10  by axial withdrawal and insertion of the cylindrical bodies. 
     Cylindrical body  22  has an axially extending sidewall  68  having a double shoulder construction including a first raised shoulder  70  of first increased radial height  72 , and a second raised shoulder  74  of second increased radial height  34 . Second raised shoulder  74  provides the noted first raised annular rib  40 . Second increased radial height  34  is greater than first increased radial height  72 . Cylindrical body  24  has an axially extending sidewall  76  having a double shoulder construction at upstream end  52  including a third raised shoulder  78  of increased radial height  72 , and a fourth raised shoulder  80  of increased radial height  34 . Fourth raised shoulder  80  provides the noted second raised annular rib  42 . Increased radial height  34  at shoulder  80  is greater than increased radial height  72  at shoulder  78 . Sidewall  76  of cylindrical body  24  has another double shoulder construction at downstream end  54  including a fifth raised shoulder  82  of increased radial height  72 , and a sixth raised shoulder  84  of increased radial height  34 . Raised shoulder  84  provides the noted third raised annular rib  44 . Increased radial height  34  at shoulder  84  is greater than increased radial height  72  at shoulder  82 . Cylindrical body  26  has an axially extending sidewall  86  having a double shoulder construction including a seventh raised shoulder  88  of increased radial height  72 , and an eighth raised shoulder  90  of increased radial height  34 . Raised shoulder  90  provides the noted fourth raised annular rib  46 . Increased radial height  34  at shoulder  90  is greater than increased radial height  72  at shoulder  88 . 
     Cylindrical body sidewall  68  has inner and outer surfaces  92  and  94 . Outer surface  94  of cylindrical body sidewall  68  at flange  60  has a radial height  28  less than the radial height  34  of outer surface  94  of cylindrical body sidewall  68  at shoulder  74  and less than or equal to the radial height  72  of outer surface  94  of cylindrical body sidewall  68  at shoulder  70 . Cylindrical body sidewall  76  has inner and outer surfaces  96  and  98 . Outer surface  98  of cylindrical body sidewall  76  at flange  62  has a radial height  72  less than the radial height  34  of outer surface  98  of cylindrical body sidewall  76  at shoulder  80  and less than or equal to radial height  72  of outer surface  98  of cylindrical body sidewall  76  at shoulder  78 . Outer surface  98  of cylindrical body sidewall  76  at flange  64  has a radial height  72  less than the radial height  34  of outer surface  98  of cylindrical body sidewall  76  at shoulder  84  and less than or equal to the radial height  72  of outer surface  98  of cylindrical body sidewall  76  at shoulder  82 . Cylindrical body sidewall  86  has inner and outer surfaces  100  and  102 . Outer surface  102  of cylindrical body sidewall  86  at flange  66  has a radial height  28  less than the radial height  34  of outer surface  102  of cylindrical body sidewall  86  at shoulder  90  and less than or equal to the radial height  72  of outer surface  102  of cylindrical body sidewall  86  at shoulder  88 . 
     Inner surface  92  of cylindrical body sidewall  68  has a radial height  104  less than the radial height  106  of inner surface  92  of cylindrical body sidewall  68  at shoulder  74  and less than or equal to the radial height  108  of inner surface  92  of cylindrical body sidewall  68  at shoulder  70 . Inner surface  96  of cylindrical body sidewall  76  at flange  62  has a radial height  108  less than the radial height  106  of inner surface  96  of cylindrical body sidewall  76  at shoulder  80  and less than or equal to the radial height  108  of inner surface  96  of cylindrical body sidewall  76  at shoulder  78 . Inner surface  96  of cylindrical body sidewall  76  at flange  64  has a radial height  108  less than the radial height  106  of inner surface  96  of cylindrical body sidewall  76  at shoulder  84  and less than or equal to the radial height  108  of inner surface  96  of cylindrical body sidewall  76  at shoulder  82 . Inner surface  100  of cylindrical body sidewall  86  at flange  66  has a radial height  104  less than the radial height  106  of inner surface  100  of cylindrical body sidewall  86  at shoulder  90  and less than or equal to the radial height  108  of inner surface  100  of cylindrical body sidewall  86  at shoulder  88 . 
     In the preferred embodiment, the noted first, third, fifth and seventh increased radial heights at the noted respective first, third, fifth and seventh shoulders  70 ,  78 ,  82 ,  88  are substantially equal to each other. Further in the preferred embodiment, the noted second, fourth, sixth and eighth increased radial heights at the noted respective second, fourth, sixth and eighth shoulders  74 ,  80 ,  84 ,  90  are substantially equal to each other. 
     In further embodiments, the noted central section includes plural central cylindrical bodies, such as  24   a  and  24   b , coupled to each other by the above described raised rib beaded coupling configuration comparable to that at annulus  36  and at annulus  38 . Cylindrical bodies  22 ,  24   a ,  24   b ,  26  are axially colinearily aligned along axis  16 . The plural central cylindrical bodies provide various exhaust aftertreatment functions, such as a diesel particulate filter, a catalyst, a muffler, and the like, and various combinations thereof. 
     The cylindrical bodies may be held together axially by any suitable means, such as by inlet and outlet pipes  18  and  20  themselves if they are sufficiently rigidly mounted, or by one or more axial clamps such as shown schematically in dashed line at  110 ,  112 , or by circumferential band clamps such as shown in dashed line at  114  around ribs or beads  40  and  42  and spanning annulus  30 , and as shown in dashed line at  116  around respective ribs or beads  44  or  46  and spanning annulus  32 . 
     The invention provides a method for servicing exhaust aftertreatment device  10  by axially moving cylindrical bodies  22  and  24  away from each other and axially moving cylindrical bodies  24  and  26  away from each other and removing cylindrical body  24 , and then installing a replacement second cylindrical body  24  by axially moving cylindrical body  22  and replacement cylindrical body  24  axially towards each other and into engagement with each other in axial sliding overlapped telescoped relation, and moving replacement cylindrical body  24  and cylindrical body  26  axially towards each other and into engagement with each other in axial sliding overlapped telescoped relation. The method involves axially sliding cylindrical body  22  and replacement cylindrical body  24  into engagement with each other without overlap of annular beads  40  and  42 , and axially sliding replacement cylindrical body  24  and cylindrical body  26  into engagement with each other without overlap of annular beads  44  and  46 , such that upon the next servicing of exhaust aftertreatment device  10 , the cylindrical bodies  22  and  24  may be moved axially away from each other without axial detent interference by annular beads  40  and  42 , and cylindrical bodies  24  and  26  may be axially moved away from each other without axial detent interference by annular beads  44  and  46 . 
     It is recognized that various equivalents, alternatives and modifications are possible within the scope of the appended claims.