Abstract:
A method is provided for wrapping a mat ( 24 ) around a core in an exhaust gas aftertreatment or acoustic device. The method includes the steps of applying a longitudinally extending strip of adhesive media to the surface of the core; securing a first end of the mat ( 24 ) to at least a part of the strip of adhesive media; wrapping the mat ( 24 ) around the core for at least a complete wrap around the core; securing a second end of the mat ( 24 ) to at least a part of the strip of adhesive media.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       MICROFICHE/COPYRIGHT REFERENCE 
       [0003]    Not Applicable. 
       FIELD OF THE INVENTION 
       [0004]    This invention relates to exhaust gas aftertreatment and/or acoustic systems and the devices used therein that utilize insulation blankets, batts and mats. 
       BACKGROUND OF THE INVENTION 
       [0005]    Batts, blankets, and/or mats are utilized in exhaust gas systems in order to provide heat insulation and/or resilient mounting structure for acoustic and aftertreatment devices of the system to control the heat exchange to and from the devices and/or provide a protective mount for a core or other fragile component of the devices. It is known to place such batts/blankets/mats between adjacent wall surfaces of such devices with the material of the batts/blankets/mats being compressed to provide a desired installed density for the material to help maintain the batts/blankets/mats in a mounted position via frictional forces between the batts/blankets/mats and the adjacent wall surfaces. Typically, the adjacent wall surfaces are defined by a core or other internal component of the device and a can or housing that surrounds the core or other internal component with the batt/blanket/mat sandwiched between core/internal component and the can/housing. 
         [0006]    Such a structure is shown in U.S. Ser. No. 12/894,712 filed Sep. 30, 2010 by Steven J. Myers, entitled “Method of Installing a Multi-Layer Batt, Blanket or Mat in an Exhaust Gas Aftertreatment or Acoustic Device”, the disclosure of which is hereby incorporated by reference. 
         [0007]    Typically the batt/blanket/mat is wrapped around the core/internal component and the can/housing is installed by forcing the wrapped core/internal component into the can/housing causing the batt/blanket/mat to be sandwiched between the adjacent wall surfaces of the core/internal component and the can/housing. Often, during the installation process, when the batt/blanket/mat is being wound around the core/internal component, the tensile force being applied allows the batt/blanket/mat to slip along the circumference of the core/internal component, making installation difficult. 
         [0008]    The present invention is directed to overcoming one or more of the problems set forth above. 
       SUMMARY OF THE INVENTION 
       [0009]    In accordance with one aspect of the present invention, a method is provided for manufacturing an exhaust gas aftertreatment or acoustic device. The method includes the steps of providing a core having an outer surface substantially cylindrical about a longitudinal axis; applying a longitudinally extending strip of adhesive media to the outer surface of the core; securing a first end of a mat to a first portion at least a part of the strip of adhesive media, said first portion being less than all of the media strip; wrapping the mat around the outer surface of the core for at least a complete wrap around the core; securing a second end of the mat to a second portion of the strip of adhesive media, said first and second portions being substantially all of the media strip; providing a housing having an inner surface; locating the mat and the core inside the housing whereby the mat is compressed between the outer surface of the core and inner surface of the housing. 
         [0010]    According to one feature of this aspect of the invention, the installing method includes a first end of the mat is in a groove configuration and the second end of the mat is in a tongue configuration. 
         [0011]    According to another feature of this aspect of the invention, the strip of adhesive media comprises of two-sided tape. 
         [0012]    According to still another feature of this aspect of the invention, the strip of adhesive media comprises of spray adhesive. 
         [0013]    In accordance with another aspect of the present invention, a method is provided for manufacturing an exhaust gas aftertreatment or acoustic device. The method includes the steps of applying a strip of adhesive media to at least a first and second end portion of a mat; securing the first end of the mat to the surface of the core along the longitudinal axis of the core; wrapping the mat around the outside surface of the core for at least a complete wrap around said core; securing the second end of the mat to the surface of the core along its longitudinal axis; providing a housing having an inner surface; locating the mat and the core inside the housing whereby the mat is compressed between the outer surface of the core and inner surface of the housing. 
         [0014]    According to one feature of this aspect of the invention, the installing method includes a first end of the mat is in a groove configuration and the second end of the mat is in a tongue configuration. 
         [0015]    According to another feature of this aspect of the invention, the strip of adhesive media comprises of two-sided tape. 
         [0016]    According to still another feature of this aspect of the invention, the strip of adhesive media comprises of spray adhesive. 
         [0017]    In accordance with another aspect of the invention, a method is provided for manufacturing an exhaust gas aftertreatment or acoustic device. The method includes the steps of: providing a core having a surface substantially cylindrical about a longitudinal axis; applying an adhesive to the surface of the core along at least part of its longitudinal axis whereby said adhesive having an adhesive surface outwardly facing from the core; securing a first end of a mat to at least a part of the adhesive; wrapping the mat around the outer surface of the core for at least one complete wrap around the core; providing a housing having an inner surface; locating the mat and the core inside the housing whereby the mat is compressed between the outer surface of the core and inner surface of the housing. 
         [0018]    In accordance with another aspect of the present invention, a method is provided for manufacturing an exhaust gas aftertreatment or acoustic device. The method includes the steps of providing a core having an outer surface substantially cylindrical about a longitudinal axis; applying a strip of adhesive media to the surface of the core along at least part of its longitudinal axis; securing a first end of a mat to at least a part of the strip of adhesive media; wrapping the mat around the outer surface of the core for at least a complete wrap around the core; applying a second strip of adhesive media to a second end of the mat; securing the second end of the mat to the outer surface of the previous wrap. 
         [0019]    According to one aspect of the invention, the strip of adhesive media comprises of two-sided tape. 
         [0020]    According to another feature of this aspect of the invention, the strip of adhesive media comprises of spray adhesive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a diagrammatic representation of an exhaust gas system employing the invention; 
           [0022]      FIG. 2  is a section view of an exhaust system component employing the invention along line  2 - 2  in  FIG. 1 ; 
           [0023]      FIG. 3  is a top view of the a core of an exhaust system component with adhesive thereon pursuant to the invention; 
           [0024]      FIG. 4  is an end view of the core of  FIG. 3  with one end of the mat secured to the core in accordance with the invention; 
           [0025]      FIG. 5  is an end view of the  FIG. 3  core with one complete wrap of the mat pursuant to the invention; 
           [0026]      FIG. 6  is a top view of the mat wrapped core of  FIG. 5 ; 
           [0027]      FIG. 7  is an end view of another embodiment of the present invention with the mat wrapped around the core multiple times. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    An exemplary exhaust gas system  10  with which the present invention may be used, is shown in  FIG. 1  in the form of a diesel exhaust gas aftertreatment system to treat the exhaust  12  from a diesel combustion process  14 , such as a diesel compression engine  16 . The exhaust  12  will typically contain oxides of nitrogen (NO x ) such as nitric oxide (NO) and nitrogen dioxide (NO 2 ) among others, particulate matter (PM), hydrocarbons, carbon monoxide (CO), and other combustion by-products. The system  10  includes one or more exhaust gas acoustic and/or aftertreatment devices or components  18 . Examples of such devices  18  include catalytic converters, diesel oxidation catalysts, diesel particulate filters, gas particulate filters, lean NO x  traps, selective catalytic reduction monoliths, burners, manifolds, connecting pipes, mufflers, resonators, tail pipes, emission control system enclosure boxes, insulation rings, insulated end cones, insulated end caps, insulated inlet pipes, and insulated outlet pipes, all of any cross-sectional geometry, many of which are known. 
         [0029]    As those skilled in the art will appreciate, some of the foregoing devices  18  are strictly metallic components with a central core  19  through which the exhaust  12  flows, and other of the devices  18  can include a core  19  in the form of a ceramic monolithic structure and/or a woven metal structure through which the exhaust  12  flows. These devices  18  are conventionally used in motor vehicles (diesel or gasoline), construction equipment, locomotive engine applications (diesel or gasoline), marine engine applications (diesel or gasoline), small internal combustion engines (diesel or gasoline), and stationary power generation (diesel or gasoline). 
         [0030]      FIG. 2  shows one example of such a device  18  for use in the system  10  in the form of a catalytic unit  20  having a catalytic core  22  with outer surface  23 , a mount mat  24 , a cylindrical inner housing or can  26  having an inner surface  27 , a heat insulating blanket or batt  28 , and a cylindrical outer housing or jacket  30 . The core  22  will typically be a ceramic substrate  32  having a monolithic structure with a catalyst coated thereon and will typically have an oval, circular or other non-round cross section centered on a longitudinal axis  33  with the housing components  26  and  30  also being cylindrical in shape and centered on the axis  33 . The mounting mat  24  is sandwiched between the outer surface  23  of the core  22  and the inner surface  27  of the can  26  to help protect the core  22  from shock and vibrational forces that can be transmitted from the can  26  to the core  22 . 
         [0031]    The heat insulating batt  28  is made of a silica fiber insulation material. Such material is known and commercially available, with one suitable example being supplied by BGF Industries, Inc. under the trade name SilcoSoft®, and another suitable example being supplied by ASGLAWO technofibre GmbH under the trade name Asglasil®. Such material is typically supplied in rolls, with the individual batts  28  being die cut to the appropriate length and width for the corresponding device  18  after the material has been taken from the roll. Preferably, the batt  28  is sandwiched or compressed in the annular gap  34  between the outer surface  36  of the can  26  and the inner surface  38  of the housing  30 . 
         [0032]    Referring to  FIGS. 3 &amp; 4 , in accordance with the present invention, the first step in installing the mounting mat  24  consists of using a clamping mechanism  38  to clamp the core  22  along its axis such that it is prevented from rotating along its axis  40 . Thereafter, a strip of adhesive media  36  is placed along the longitudinal axis  40  of the outer surface  23  of the core  22 . 
         [0033]    In the described embodiment, commercially available double sided tape is used as the adhesive media  36 . In addition it is contemplated that other adhesives including spray adhesive can be used as adhesive  36 . 
         [0034]    The strip of adhesive media  36  is placed on the outer surface  23  of the core  22  such that the width  37  of adhesive media  36  is great enough to adequately grip the end of the mat  24  as its rolled around the core  22  as described herein. In one embodiment, the strip of adhesive media  36  is at least as wide as the tongue end  42  and groove end  44  of the mat  24 . It should be appreciated that the adhesive media  36  can also be place on the ends of the mat alone or in combination with the core  22  providing the same advantages as described herein. 
         [0035]    Referring to  FIG. 4 , once the adhesive media  36  is placed on the outer surface  23  of the core  22 , the core  22  is rotated along its longitudinal axis  40  until the adhesive media strip  36  is generally located along the bottom of the core  22 . According to the invention, the groove end  44  of the mat  24  is then placed below the core  22 . The core  22  is lowered until it comes into contact with the groove end  44  of the mat  24  such that approximately one half of the width  37  of the adhesive media  36  previously placed on the surface  23  of the core  22  adheres and secures the groove end  44  of the mat  24  to the core  22 . 
         [0036]    Referring to  FIGS. 5 &amp; 6 , the core  22  is then rotated along its longitudinal axis  40  such that the mat  24  is wrapped around the outer surface  23  of core  22  transverse to the longitudinal axis  40  so that the mat  24  is in a constant position relative to the core  22  with the edges  32 ,  33  of the mat  24  being perpendicular to longitudinal axis  40 . The adhesive media  36  secures the mat  24  to the core  22  such that the mat  24  does not slip transversely as the core  22  is rotated as described herein. 
         [0037]    Once the mat  24  is wrapped around the outer surface  23  of the core  22 , the tongue end  42  of the mat  24  is placed into the groove end  44  of the mat  24  and secured to the core  22  by adhering it to the approximately one half of the width  37  not adhered to the groove end  44  previously secured to the core  22 . In this configuration, the mat  24  is attached to the core  22  such that it is easily moved to a separate location for insertion into the can  26 . 
         [0038]      FIG. 7  discloses a second embodiment wherein the catalytic unit  20  employs a multi layer mat design. With a multi layer mat design, the adhesive media  36  is placed on the outer surface  23  of the core  22  such that the width  37  of adhesive media  36  is great enough to adequately grip one end of the mat  24  as its rolled around the core  22  as described herein. It should be appreciated that the adhesive media  36  can also be place on the end of the mat alone or in combination with the core  22  providing the same advantages as described herein. 
         [0039]    The core  22  is lowered until it comes into contact with one end of the mat  24  such that the adhesive media  36  previously placed on the surface  23  of the core  22  adheres and secures the end  50  of the mat  24  to the core  22 . 
         [0040]    The mat  24  is wrapped around the core  22  for the first wrap  46  as described above. Subsequent to the first wrap, the mat  24  is wrapped about the longitudinal axis  33 , a successive number of times. As shown in  FIG. 7 , the embodiment shown contains one successive wrap  48 . This final wrap  48  is accomplished by wrapping the mat  24  around the previous wrap  46  of the mat  24  transverse to the longitudinal axis. It should be appreciated that the number of successive wraps is determined based upon the requirements of the specific system. 
         [0041]    It should also be appreciated that the method described allows for a more efficient installation process and allows the mat and core to be easily moved before installation into a can. In addition, the adhesive helps to reduce unsupported corners of the batt/blanket/mat during installation. 
         [0042]    It should further appreciated that while the invention has been described herein in connection with a diesel combustion process in the form of a diesel compression engine  16 , the invention may find use in devices that are utilized in exhaust gas systems for other types of combustion processes, including other types of internal combustion engines, including, for example, internal combustion engines that use gasoline or other alternative fuels.