Abstract:
An elastomeric assembly is disposed within an aperture defined by a supporting structure of a vehicle. The elastomeric assembly is movable between a first position where the elastomeric assembly can move axial within the aperture and a second position where the elastomeric assembly is prohibited from moving axially within the aperture.

Description:
FIELD 
       [0001]    The present disclosure relates to a mounting arrangement for an exhaust system of a vehicle. More particularly, the present disclosure relates to an exhaust isolator which is mounted directly to a vehicle&#39;s frame or underbody, thus eliminating the need for brackets, bolts, welded frame nuts, clipped in frame nuts or the like. 
       BACKGROUND 
       [0002]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0003]    Typically, automotive vehicles, including cars and trucks, have an internal combustion engine which is coupled to at least a transmission and a differential for providing power to the driven wheels of the vehicle. An engine exhaust system which typically includes an exhaust pipe, a catalytic converter, a muffler and a tail pipe is attached to the engine to quiet the combustion process, to clean the exhaust gases and to route the products of combustion away from the engine. The exhaust system is supported by exhaust mounts or isolators which are positioned between the exhaust system and the frame, the underbody or some other supporting structure of the vehicle&#39;s body. In order to prevent engine movement and/or vibrations from being transmitted to the vehicle&#39;s body, the exhaust mounts or isolators incorporate flexible mounting members or elastic suspension members to isolate the vehicle&#39;s body from the exhaust system. 
         [0004]    Typical prior art exhaust mounts or isolators include an upper hanger which is attached to the vehicle&#39;s frame or other support structure of the vehicles&#39; body. The upper hanger extends from the support structure such that it positions an elastomeric isolator at the proper location to accept a lower hanger which extends from the elastomeric isolator to one of the exhaust system&#39;s components. The elastomeric isolator is secured in a specific location between the upper hanger and the lower hanger. Typically, the upper hanger includes assembly hardware such as stamped brackets, bolts, welded frame nuts, clip-in frame nuts and/or formed rods which are utilized to secure the upper mount to the frame or other supporting structure and to secure the elastomeric isolator to the upper mount. This hardware increases the costs and the amount of labor necessary for the construction and assembly of the vehicle. 
       SUMMARY 
       [0005]    The present disclosure describes an engine mount or isolator which is mounted directly to the vehicle&#39;s frame or other supporting structure of the vehicle&#39;s body. The direct attachment of the exhaust mount or isolator eliminates the need for the upper hanger and all of the associated hardware. The exhaust mount or isolator can be fit directly within an aperture formed in the support structure. The elastomeric portion of the exhaust mount or isolator includes a hole which accepts a support rod or lower hanger which is attached to a component of the exhaust system. The support rod or lower hanger can be formed to position the component of the exhaust system in the desired location. The exhaust mount or isolator includes a push and turn mounting system which simplifies assembly of the exhaust mount or isolator to the vehicle. 
         [0006]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0007]    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. 
           [0008]      FIG. 1  is a perspective view of an exhaust system attached to a supporting structure of a vehicle with exhaust isolators in accordance with the present disclosure; 
           [0009]      FIG. 2  is an enlarged perspective view of one of the exhaust isolators illustrated in  FIG. 1 ; 
           [0010]      FIG. 3  is a perspective view of the exhaust isolator illustrated in  FIGS. 1 and 2 ; 
           [0011]      FIGS. 4A-4C  are perspective views illustrating the assembly of the exhaust isolator of the present disclosure; 
           [0012]      FIGS. 5A-5B  are perspective views partially in cross-section illustrating the inserts in the exhaust isolator of the present disclosure; 
           [0013]      FIG. 6  is a perspective view in cross-section illustrating the exhaust isolator of the present disclosure; 
           [0014]      FIG. 7  is a front perspective view of the inserts of the exhaust isolator of the present disclosure; 
           [0015]      FIG. 8  is a rear perspective view of the inserts of the exhaust isolator of the present disclosure; and 
           [0016]      FIG. 9  is an end view of the exhaust isolator in accordance with the present disclosure illustrating an orientation feature of the exhaust isolator. 
       
    
    
       [0017]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0018]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0019]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. There is shown in  FIG. 1 , an exhaust mounting system in accordance with the present disclosure which is identified generally by the reference numeral  10 . Exhaust mounting system  10  attaches an exhaust system  12  to a supporting structure  14  of a vehicle. The vehicle includes an internal combustion engine (not shown), an unsprung mass including wheels and a suspension system (not shown) and a sprung mass which includes a vehicle body (not shown) which is supported by supporting structure  14 . Exhaust system  12  is connected to the engine of the vehicle and exhaust system  12  routes the products of combustion of the engine to the rear of the vehicle. The internal combustion engine powers the wheels of the vehicle through a transmission (not shown) and a differential (not shown). 
         [0020]    Exhaust system  12  comprises an intermediate pipe  22 , a muffler  24 , a tailpipe  26  and a plurality of exhaust isolator assemblies  30 . Intermediate pipe  22  is typically connected to a catalytic converter (not shown) which is connected to an exhaust pipe (not shown) which is in turn connected to an exhaust manifold (not shown) which is one of the components of the vehicle&#39;s internal combustion engine. The catalytic converter may be connected to a single exhaust pipe which leads to a single exhaust manifold or the catalytic converter can be attached to a branched exhaust pipe which leads to a plurality of exhaust manifolds. Also, intermediate pipe  22  can be connected to a plurality of catalytic converters which connect together prior to reaching muffler  24  using a branched intermediate pipe  22  or the vehicle can have a plurality of exhaust manifolds, connected to a plurality of exhaust pipes, connected to a plurality of catalytic converters, connected to a plurality of intermediate pipes, connected to a plurality of mufflers, connected to a plurality of exhaust pipes. The present disclosure is applicable to the above described exhaust systems as well as any other exhaust system known in the art. 
         [0021]    Exhaust system  12  is utilized to route the exhaust gases from the vehicle&#39;s engine to the rear area of the vehicle. While the exhaust gases travel from the engine to the rear of the vehicle through exhaust system  12 , the catalytic cleaner cleans the exhaust gases and muffler  24  quiets the noises associated with the combustion process of the vehicle&#39;s engine. Exhaust isolator assemblies  30  provide for the support of exhaust system  12  underneath the vehicle and they operate to prevent engine movement and other vibrations from being transmitted to the vehicle&#39;s body. In addition, exhaust isolator assemblies  30  provide proper positioning and alignment for exhaust system  12  during assembly of exhaust system  12  and during the operation of the vehicle. 
         [0022]    Referring now to  FIGS. 2-8 , exhaust isolator assembly  30  comprises an elastomeric assembly  40  and an hanger pin  42 . Elastomeric assembly  40  comprises a first insert  44 , a second insert  46  each of which is molded into an elastomeric body  48 . 
         [0023]    Elastomeric assembly  40  is a single-hole shear hub design where elastomeric body  48  defines a hole  50  which is designed to accept hanger pin  42 . Hanger pin  42  is secured to one of the components of exhaust system  12  and elastomeric assembly  40  is attached to the frame or supporting structure  14  of the vehicle. Thus, exhaust system  12  is secured to the vehicle through elastomeric assembly  40 . Elastomeric assembly  40  also defines a plurality of lobe flanges  52  on one end of elastomeric assembly  40  and a hexagonal structure  54  located on the end of elastomeric assembly  40  opposite to the plurality of lobe flanges  52 . 
         [0024]    Elastomeric body  48  defines an outer circumferential void  56  and an inner circumferential void  58 . While voids  56  and  58  are illustrated as being asymmetrical with respect to hole  50 , it is within the scope of the present disclosure to have voids  56  and  58  symmetrical to hole  50 . The design of voids  56  and  58 , specifically their thickness, will determine the amount of travel until the rate of elastomeric assembly  40  spikes up due to the closing of voids  56  and  58 . Until the closing of voids  56  and  58 , the radial loads cause pure shear stress in elastomeric body  48  regardless of the loading direction. 
         [0025]    The loading direction of elastomeric assembly  40  can be in any radial direction around hole  50 . Tuning for rate and deflection in selective directions can be accomplished independently from other directions by altering voids  56  and  58  in the appropriate circular sectors. As can be seen in  FIG. 6 , void  56  overlaps with void  58 . The larger the overlap between voids  56  and  58 , the lower the stresses and stiffness for elastomeric assembly  40 . The peak loads bottom out voids  56  and  58  and start to impart compressive stress to elastomeric body  48  from hanger pin  42  and first and second inserts  44  and  46 . As illustrated in  FIGS. 6-8 , first and second inserts  44 ,  46  extend around the inner and outer regions of elastomeric body  48 . The bottoming of voids  56  and  58  and the subsequent compression of elastomeric body  48  makes the compressive stresses spread out rather than having the compressive stresses concentrated in a spoke or leg cross-section as in the prior art. This permits the stress magnitude to decrease as well as changing the stress loading to a more favorable type. 
         [0026]    Hanger pin  42  is inserted through hole  50  during the installation of exhaust system  12 . Hanger pin  42  is a formed rod which can include compound bends such that a first end is positioned to axially engage hole  50  and a second, opposite end is designed to mate with and be secured to a component of exhaust system  12 . As illustrated, a different hanger pin  42  is used for each exhaust isolator assembly  30  but it is within the scope of the present disclosure to utilize as many common hanger pins  42  as the design for the specific application allows. An annular barb  60  is formed on the insertion end of each hanger pin  42  to resist the removal of the hanger pin  42  from hole  50 . 
         [0027]    Elastomeric assembly  40  is designed to be assembled into a flanged aperture  66  defined by supporting structure  14  of the vehicle. As illustrated in  FIG. 3 , aperture  66  defines a plurality of lobes  68  which are designed to correspond with and mate with the plurality of lobe flanges  52  defined by elastomeric assembly  40 . The assembly of elastomeric assembly  40  is illustrated in  FIGS. 4A to 4C . First, as illustrated in  FIG. 4A , the plurality of lobe flanges  52  defined by elastomeric assembly  40  are aligned with the plurality of lobes  68  defined by aperture  66 . A clearance around the entire circumference of elastomeric assembly  40  is provided between aperture  66  and elastomeric assembly  40  to allow the insertion of elastomeric assembly  40  into aperture  66 . Elastomeric assembly  40  is pushed axially into aperture  66  as shown by the arrow in  FIG. 4A  until a flange  68 , formed as part of hexagonal structure  54 , seats against the surface of supporting structure  14  that defines aperture  66 . Second, as illustrated in  FIG. 4B-4C , elastomeric assembly  40  is rotated to misalign the plurality of lobe flanges  52  with the plurality of lobes  68  and thus lock elastomeric assembly  40  to supporting structure  14 . A stop  70  defined by elastomeric assembly  40  contacts the side of aperture  66  when elastomeric assembly  40  has been fully rotated. Hexagonal structure  54  is provided to assist in the rotation of elastomeric assembly  40 . A gap  72  defined between the plurality of lobe flanges  52  and flange  68  accommodate the flange portion of supporting structure  14  that defines aperture  66 . 
         [0028]    While elastomeric assembly  40  is designed to have a clearance fit with aperture  66  when the plurality of lobe flanges  52  are aligned with the plurality of lobes  68 , the outside radial surface forming gap  72  between the plurality of lobe flanges  52  and flange  68  are designed to have an interference fit with the flanged portion of supporting structure  14  which forms the inside diameter of aperture  66  which mates with the outside radial surface forming gap  72 . In this way, the compression of elastomeric body  48  within gap  72  will act as means for retaining elastomeric assembly  40  in its rotated and locked position in aperture  66 . 
         [0029]    While stop  70  is designed to indicate when elastomeric assembly  40  is in its fully assembled and locked position, it is within the scope of the present disclosure to form an indicator  80  on elastomeric assembly  40  as indicated in  FIG. 7 . Indicator  80  is designed to align with a mark or indicator (not shown) on supporting structure  14  when elastomeric assembly  40  is properly installed. While indicator  80  is illustrated in  FIG. 7  as being located on second insert  46 , indicator  80  will remain visible on elastomeric assembly  40  after the molding of elastomeric body  48 . In addition, it is within the scope of the present disclosure to have indicator  80  being formed only by elastomeric body  48 . 
         [0030]    First and second inserts  44  and  46  are manufactured from plastic or metal and are illustrated in  FIGS. 7 and 8 . First insert  44  defines a cylindrical portion  82  which surrounds hole  50  and a flanged portion  84  which extends radially outward from cylindrical portion  82 . Second insert  46  is disposed around first insert  44  and it defines indicator  80 , a plurality of lobe flanges  86  and a stop  88 . The plurality of lobe flanges  86  correspond to the plurality of lobe flanges  52  and stop  88  corresponds to stop  70 . While the plurality of lobe flanges  52  and stop  70  are illustrated as including the plurality of lobe flanges  86  and stop  88 , respectfully, it is within the scope of the present disclosure to have the plurality of lobe flanges  52  and stop  70  formed only from elastomeric body  48 . 
         [0031]    As illustrated in  FIG. 6 , second insert  46  includes a radially flange  90  extending radially outward from lobe flange  86 . Flange  90  is included in each of the plurality of lobe flanges  52 . Each flange  90  defines a radially outwardly extending flange  92  on elastomeric assembly  40  which entraps the flanged portion of supporting structure  14  that forms aperture  66  between flange  92  and flange  68 . 
         [0032]      FIG. 9  illustrates an embodiment of the present disclosure where circumferential orientation of elastomeric assembly  40  with respect to aperture  66  can be achieved. Circumferential orientation may be required when the tuning rate and deflection in selective directions has been incorporated into elastomeric assembly  40 . As illustrated in  FIG. 9 , one of the plurality of lobes  68   a  and one of the plurality of lobe flanges  52   a  extends a larger distance radially from hole  50  than the other two of the plurality of lobes  68   b ,  68   c  and the other two of the plurality of lobe flanges  52   a ,  52   b . By having only one of the lobes  68   a  and lobe flanges  52   a  extend radially farther out than lobes  68   b ,  68   c  and lobe flanges  52   b  and  52   c , elastomeric assembly  40  can only be inserted into aperture  66  in one single circumferential orientation. 
         [0033]    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. The same 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.