Patent Publication Number: US-2015059905-A1

Title: Hybrid marman clamp design

Description:
TECHNICAL FIELD 
     The present invention generally relates to a pipe assembly for an exhaust system used in vehicles and, more particularly, to a pipe assembly having corrugated conduit coupled to a rigid pipe with a clamp and utilizing a shim ring to provide a connection there between. 
     BACKGROUND 
     Vehicles such as trucks, buses, and other similar automobiles are equipped with an exhaust system to convey hot exhaust gases and byproducts of combustion from an internal combustion engine to the ambient atmosphere. The exhaust system utilizes various emission control devices, such as mufflers, resonators, catalytic converters, and the like. The emission control devices are connected to form the exhaust system. Connections for connecting the control devices are made using a corrugated conduit, and joints are sealed using different joint types, such as full marman, half marman, bolted, and slip fit joint. 
     The exhaust system is subjected to thermal stresses associated with the handling of hot exhaust gases and vibration stresses from vibration sources such as the engine and the operation of the vehicle such a digging or excavating. As the exhaust system are subject to such stresses, the joints leak. The leakage can lead to eroding of manifold, which may contribute to carbon monoxide in passenger cabin. While various solutions have been developed to provide arrangements that can solve the problem cited above, there is still room for development. Thus, a need persists for further contribution in this area of technology. 
     The present disclosure is directed towards the problem stated above. 
     SUMMARY 
     In an embodiment, a pipe assembly for an exhaust system is provided. The pipe assembly includes a pipe having a first end and a second end. The first end of the pipe includes a shoulder having an inclined lip. The inclined lip is facing outward from the first end of the pipe. The second end of the pipe is coupled to an internal combustion engine. Further, the pipe assembly includes a corrugated conduit. The corrugated conduit includes a collared end. The collared end abuts the inclined lip on the first end of the pipe thereby forming a joint with the pipe. Further, a shim ring is disposed on the joint. The shim ring is circumferentially contractible. Furthermore, a clamp is provided. The clamp is configured to circumference the joint and compresses the shim ring there between to form a seal at the joint. 
     Other features and advantages of the invention will become apparent to those skilled in the art, upon review of the following detailed description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a pipe assembly for an exhaust system in accordance with an embodiment of the present disclosure. 
         FIG. 2  is an exploded view of a pipe assembly for an exhaust system in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed embodiments of the present disclosure are described herein with reference to  FIG. 1  and  FIG. 2 . The specific structural and functional details disclosed herein are intended to be exemplary and should not be interpreted as limiting the disclosure. 
       FIG. 1  illustrates a sectional view of a pipe assembly  100  for an exhaust system in accordance with an embodiment of the disclosure. The pipe assembly  100  comprises a pipe  105 , a corrugated conduit  110 , a shim ring  115 , and a clamp  120 . The pipe  105 , the corrugated conduit  110 , the shim ring  115 , and the clamp  120  have a circular transverse cross sectional configuration. The pipe assembly  100  couples the pipe  105  with emission control devices (not shown in  FIG. 1 ). For example, the pipe assembly  100  can include the pipe  105  that can be used to connect to an end section of an exhaust manifold or a mouth piece of an emission control/exhaust after treatment device. In an embodiment, pipe  105  can have a first end  125  and a second end  130 . The first end  125  can be configured to be connected to a corrugated pipe, such as corrugated conduit  110 . The first end  125  of the pipe  105  has shoulder  135 , such that outer end of the shoulder  135  has an inclined lip facing outward. In other words, the outer end of the shoulder  135  has a taper section starting from the outer diameter of the pipe  105  and ends before the inner diameter. Hence the outer section of the shoulder  135  is inclined to form a lip. 
     The second end  130  of the pipe can be connected to an exhaust treatment device, a tail pipe, a muffler, or any other emission control device. It can be contemplated that the second end  130  of the pipe  105  can be connected or joined or an integral part of any component of an exhaust system. For example, the end section of an exhaust manifold can be designed to have mouthpiece section similar to the first end  125 . 
     Further, the pipe assembly  100  is shown to include a corrugated conduit  110 . The corrugated conduit  110  can be describe as a conduit with a bellow shaped member having alternate crest and troughs on the periphery. The ends of the corrugated conduit  110  are collared to conform to the shape of the inclined lip of the pipe  105 . In other words, the collared ends of the corrugated conduit  110  are designed to match with lip design on the first end  125 . It is to be noted that both the pipe  105  and the corrugated conduit  110  can be hollow cylindrical pipe to accommodate the flow of fluid or gases, such as exhaust gases, in an embodiment of the current disclosure. 
     The shim ring  115  can be a tapered or flat ring. In other words, the shim ring  115  can be a wedge shaped ring made of suitable material such as latex, resilient rubber, laminated stacked foil of metal. In general shim ring  115  can be a ring that can be configured to contract circumferentially. 
     The clamp  120  can be an annular band shape element that can be disposed circumferentially over a cylinder and tightened around the cylinder. In other words, the clamp  120  can be positioned over a cylindrical body and can be compressed over the cylindrical body to form a seal or apply pressure from outside. The assembly of the components in the present disclosure, including the placement and juxtaposition of components, is further illustrated in  FIG. 2 . 
       FIG. 2  is an exploded view of the pipe assembly  100  for an exhaust system in accordance with an embodiment of the present disclosure. The pipe assembly  100  is described in conjunction with the elements described in  FIG. 1 .  FIG. 2  illustrates the exploded view of the pipe  105 , the corrugated conduit  110 , the shim ring  115  and the clamp  120 . 
     As described in  FIG. 1 , the pipe  105  is cylindrical in shape with two ends, the first end  125  and the second end  130 . The first end  125 , at point  205  is an open end with a shoulder  210  and an outside diameter  215 . Further, the shoulder  210  present on the first end  125  of the pipe  105  has an inclined lip  220 . In other words, the shoulder can be a circumferential rim with a tapered face at the outer end of the pipe  105 . 
     The corrugated conduit  110  comprises an open end  225 . The corrugated conduit  110  further comprises a corrugated section  230  with a series of corrugations spaced at a regular interval. The corrugated conduit  110  can be of a suitable internal diameter  235  to accommodate the flow of gases such as exhaust gases from an engine. Also, at the open end  225 , the external diameter  240  of the corrugated conduit  110  forms a collar  250 . The corrugated conduit  110  is also shown to include a neck portion  245  located between open end  225  and the corrugated section  230 . In other words, the corrugated conduit  110  has a circular transverse cross-sectional configuration, with the neck portion  245  having a smooth cylindrical surface between the open end  225  and the corrugated section  230 . The neck portion  245  of the corrugated conduit  110  proceeds into the collar  250 , with the external diameter  240 . 
     The collar  250  can be configured to abut to the inclined lip  220  of the pipe  105 . It is to be noted that the outside diameter  215  of the pipe  105  is equal to or less than the external diameter  240  of the corrugated conduit  110 , such that the pipe  105  is adapted to be received within the open end  225  of the corrugated conduit  110  in a sealed manner. 
       FIG. 2  is also shown to include the shim ring  115 . The shim ring  115  can be a cylindrical band with circular edges. The shim ring  115  has a circular transverse cross-sectional configuration with an outside diameter  255 . The outside diameter  255  of the shim ring  115  can be larger than the internal diameter  235  of the corrugated conduit  110  such that the shim ring  115  can be adapted to fit over the neck portion  245  of the corrugated conduit  110 . In one embodiment, the shim ring  115  can also be placed over the neck portion  245 , abutting the collar  250  of the corrugated conduit  110 . The shim ring  115  can be made of a material that can withstand hot exhaust gases temperature. For example, the shim ring  115  may be made of steel. It will be evident to a person with ordinary skills in the art that the above-mentioned example nowhere limits the invention to the use of steel for manufacturing the shim ring  115 . In an embodiment, the shim ring  115  can be made from any material that can withstand high pressure and temperature condition existing in a known in the art exhaust system. 
     As described above, the shim ring  115  can be disposed circumferentially around the neck portion  245  of the corrugated conduit  110 . Further, the collar  250  of the corrugated conduit  110  can be abutted with the inclined lip  220  to cause a joint between the pipe  105  and the corrugated conduit  110 . 
     Further, the joint between the corrugated conduit  110  and the pipe  105 , including the shim ring  115 , is implemented by the clamp  120 . The clamp  120  has an annular band shape structure. In other words, the clamp  120  can be flat metal band that can be configured to circumference around the joint. Further, a pair of ears  260  with an aperture  265  are integrated and extended from the clamp  120  for receiving a suitable mechanical fastener, such as a nut and bolt (not shown in the FIG.) that may be used to tighten to draw the pair of ears  260  together. In other words, the clamp  120  can be a broken circumferential metal band than can have a pair of lobes or ears  260  extend at the broken end. The pair of lobes or ears  260  can have the aperture  265 , such that the broken ends can be drawn together by tightening the pair of ears  260  and thus hold the corrugated conduit  110  around the pipe  105 . In an embodiment, the pair of ears  260  of the clamp can be drawn close, to compress the shim ring  115  located under the clamp  120 . 
     Hence, the pipe  105  is received within the corrugated conduit  110  such that the collar  250  of the corrugated conduit  110  abuts to the inclined lip  220  of the pipe  105 . The shim ring  115  is sandwiched between the corrugated conduit  110  and the clamp  120 , and is thus compressed when clamp  120  is tightened thereby forming an effective seal. The shim ring  115  thus substantially fills in the area or gap between the clamp  120  and the corrugated conduit  110 , and acts as a wedge. The shim ring  115  redistributes the load from the clamp  120  over a larger area of the corrugated conduit  110 . This prevents high load concentrations due to the potential line contact of the clamp  120  on the corrugated conduit  110 . Thus, a secure and gas tight seal is formed at the joint, with the clamp  120  providing a secure mechanical connection and the shim ring  115  providing an effective seal. 
     In the embodiments discussed above, the disclosure provides a clamp design as a solution for providing gas-tight seal joints. The clamp design essentially replicates a pseudo half marman clamp using the manifold end connections configured for a full marman joint. The shim ring  115  can be inserted under the clamp  120  to provide the sealing force that a half marman joint would typically provide. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure provides an improved clamp design that applies generally to an exhaust system used in vehicles. The present disclosure finds specific applicability in connecting an exhaust manifold/pipe with a corrugated conduit  110 , which is further connected to other emission control devices. When in operation, the exhaust manifold/pipe collects exhaust from an engine (not shown in the FIG.) and directs the exhaust along the corrugated conduit  110  though other emission control devices or into the atmosphere. 
     Corrugated conduits are needed along the way to account for vibration and assembly. The connection between various components and corrugated conduit  110  may be made using the clamp design disclosed in the embodiments above. Other joints, for example a full marman joint, are not always as robust as desired and may lead to exhaust leakage, especially in a high temperature exhaust environment. The disclosed clamp design discussed in the disclosure provides a more rigid and stable joint to be used in the exhaust assembly. The disclosure provides a retrofit to fix leaking exhaust manifolds. The disclosed joint type replicates a pseudo half marman clamp using the existing components that were configured for a full marman joint. 
     The disclosed clamp design also acts as a solution for transforming existing full marman joint to a hybrid half marman joint. The transformation can be done by using same components designed for a full marman joint. An embodiment of the present disclosure uses the shim ring  115  on the corrugated conduit  110  under the clamp  120 . The shim ring  115  redistributes the load from the clamp  120  over the larger area of the corrugated conduit  110 , thereby preventing high load concentrations. 
     It should be understood that the above description is intended for illustrative purposes only and is not intended to limit the scope of the present disclosure in any way. Thus, those skilled in the art will appreciate that other aspects of the disclosure can be obtained from a study of the drawings, the disclosure, and the appended claim.