Abstract:
A vehicle suspension system utilizes a resilient rod and bracket configuration to replace standard torque rods. Resilient rods are used to couple an axle member to a vehicle member. The axle member includes an axle bracket and the vehicle member includes a vehicle bracket. Upper and lower resilient rods are coupled to the axle and vehicle brackets at each axle end. The resilient rods are pogo rods that utilize a pair of resilient grommets at each rod end that are compressed against a bracket flange by a pair of rigid cups to provide a resilient mount interface. This resilient mount interface at each rod end allows relative movement between the axle and vehicle brackets and each rod in up to ten degrees of freedom.

Description:
TECHNICAL FIELD  
       [0001]     The subject invention relates to a vehicle suspension that utilizes a unique pogo rod and bracket configuration to replace standard torque rods for controlling suspension and axle travel.  
       BACKGROUND OF THE INVENTION  
       [0002]     Vehicle suspension systems are used to absorb road load inputs and other vibrations to provide a smooth and comfortable ride. Vehicle suspension systems include various components that couple an axle member to a vehicle frame or sub-frame. A typical suspension system includes upper and lower torque rods that extend between each end of the axle member and the vehicle frame. Each end of the torque rod is connected to an associated vehicle or axle bracket with a bushing mount. This requires complicated bracket assemblies and multiple fastening elements, which is undesirable.  
         [0003]     Vehicle suspension systems also often include a stabilizer bar that is used to increase roll rigidity and improve steering stability. Typically, the stabilizer bar is connected to lower control arms, which are mounted to a wheel component, such as a knuckle. To further improve suspension characteristics, a transverse torque rod is often used to connect one axle end to the vehicle frame at an opposite axle end. Again, these connection interfaces for the stabilizer bar and transverse torque rods require complicated bracket configurations.  
         [0004]     Further, these bushing and bracket type connection interfaces have limited degrees of relative movement. Suspension systems are needed that more effectively absorb road load inputs and vibrations without adding additional hardware, which overcomplicates the system. Thus, there is a need for a simplified suspension connection interface between an axle and a vehicle frame that provides a more comfortable vehicle ride.  
       SUMMARY OF THE INVENTION  
       [0005]     A vehicle suspension system utilizes a resilient rod and bracket configuration to replace standard torque rods. Resilient rods are used to couple an axle member to a vehicle member. The axle member includes an axle bracket and the vehicle member includes a vehicle bracket. Upper and lower resilient rods are coupled to the axle and vehicle brackets at each axle end.  
         [0006]     The resilient rods are pogo rods that utilize a pair of resilient grommets at each rod end that are compressed against a bracket flange by a pair of rigid cups to provide a resilient mount interface. This resilient mount interface at each rod end allows relative movement between the axle and vehicle brackets and each rod end in up to ten degrees of freedom.  
         [0007]     The vehicle brackets and axle brackets are simplified as each bracket has to have only one opening for each rod end. Thus, the axle bracket only has two (2) openings, one for the upper resilient rod and one for the lower resilient rod. Correspondingly, the vehicle bracket only has two (2) openings, one each for the upper and lower resilient rods.  
         [0008]     The pogo rods can be used to replace standard torque rods in all locations within a vehicle suspension, including a transverse torque rod. Further, the pogo rods can be used to replace linkage traditionally used for connecting a stabilizer bar between the axle member and the vehicle member. Further, the pogo rods are easily incorporated into suspensions for I beam or tubular front or rear axles.  
         [0009]     These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a schematic view of an axle assembly and a vehicle suspension system incorporating the subject invention.  
         [0011]      FIG. 2  is a schematic side view of one suspension configuration.  
         [0012]      FIG. 3  is a perspective view of one suspension rod assembly incorporating the subject invention.  
         [0013]      FIG. 4  is a second view of one end of the suspension rod assembly of  FIG. 3 .  
         [0014]      FIG. 5  is a side view of one example bracket and rod configuration for an I-beam axle member.  
         [0015]      FIG. 6  is one example configuration of a bracket as used in the configuration of  FIG. 5 .  
         [0016]      FIG. 7  is one example rod and bracket configuration for a tubular axle.  
         [0017]      FIG. 8  is a schematic top view of a five rod configuration for an axle assembly.  
         [0018]      FIG. 9  is a schematic view of a transverse rod connection for a non-drive axle.  
         [0019]      FIG. 10  is a perspective view of a transverse rod connection for a drive axle.  
         [0020]      FIG. 11  is a schematic view of a stabilizer bar connection.  
         [0021]      FIG. 12  is a magnified view of one connection interface of a stabilizer bar.  
         [0022]      FIG. 13  is a schematic side view of a leaf spring suspension configuration.  
         [0023]      FIG. 14  is a schematic view showing rod placement for the leaf spring suspension of  FIG. 13 .  
         [0024]      FIG. 15  is one example shock absorber configuration. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]      FIG. 1  shows an axle  10  extending between first  12  and second  14  wheels. A suspension system  16  is mounted between the axle  10  and a vehicle sub-frame or frame  18 . The axle  10  includes a first axle end  20  at the first wheel  12  and a second axle end  22  at the second wheel  14 . The first  20  and second  22  axle ends each include an axle bracket  24 . A corresponding vehicle bracket  26  is also mounted to the vehicle frame  18  adjacent each of the first  20  and second  22  axle ends. Pogo rods  30  extend between each axle bracket  24  and corresponding vehicle bracket  26 . The pogo rods  30  replace standard torque rods that have been traditionally used in vehicle suspensions.  
         [0026]     In the example shown, each of the first  20  and second  22  axle ends includes an upper pogo rod  30   a  and a lower pogo rod  30   b  (indicated by dashed lines). The suspension system  16  could also include a transverse pogo rod  32  that extends from an axle bracket  34  at one axle end to a vehicle bracket  36  mounted to the vehicle frame  18  at an opposite axle end.  
         [0027]     One end of the suspension system  16  is shown in greater detail in  FIG. 2 . The vehicle bracket  26  includes a vehicle mount portion  38  and a flange portion  40 . The axle bracket  24  includes an axle mount portion  42  and a flange portion  44 . The upper  30   a  and lower  30   b  pogo rods extend between the flange portions  40 ,  44  and are generally parallel to each other. An air spring  46  is positioned above the axle  10  and a stabilizer bar  48  is mounted to the axle  10 . The air spring  46  is also mounted to the vehicle frame  18  by bracket  50 . The stabilizer bar  48  extends from one axle end to an opposite axle end. The stabilizer bar connection interface to the axle  10  will be discussed in greater detail below.  
         [0028]     In this example, the axle  10  comprises a non-drive axle having an I-beam configuration as shown. The axle mount portion  42  of the axle bracket  24  is mounted to an upper surface of the axle  10 . The vehicle mount portion  38  of the vehicle bracket  26  is mounted to the vehicle frame  18 , which could comprise a longitudinally extending channel beam, for example. The upper  30   a  and lower  30   b  pogo rods extend generally parallel to each other between the flange portions  40 ,  44  of the vehicle  26  and axle  24  brackets. Another pogo connection  31  extends between the vehicle frame  18  and lower pogo rod  30   b  as shown.  
         [0029]     The pogo rod  30  is shown in greater detail in  FIGS. 3-4 . Each of the upper  30   a , lower  30   b , and transverse  32  pogo rods has a configuration similar to that shown in  FIGS. 3-4 . The pogo rod  30  includes a rod body  52  having a first rod end  54  and a second rod end  56 . At each of the first  54  and second  56  rod ends are first  58  and second  60  elastomeric components. Preferably, the first  58  and second  60  elastomeric components comprise resilient grommets made from urethane material, however, other resilient materials could also be used. First  62  and second  64  rigid cups are positioned outwardly of the first  58  and second  60  elastomeric components such that the first  58  and second  60  elastomeric components are sandwiched between the first  62  and second  64  rigid cups.  
         [0030]     Preferably, the first  54  and second  56  rods ends are threaded such that the first  62  and second  64  rigid cups are threadably attached to the rod body  52 . The first  62  and second  64  rigid cups are preferably formed from a steel material, however, other rigid materials could also be used. Jam nuts  66  could optionally be used to further secure and hold the first  62  and second  64  rigid cups in place.  
         [0031]     As shown in  FIG. 4 , the first  58  and second  60  elastomeric components are pressed against a bracket flange  68 . An example bracket flange  68  is shown in  FIG. 4 . This example bracket flange  68  corresponds to the flange portions  40 ,  44  of the vehicle bracket  26  and axle bracket  24 . The first  62  and second  64  rigid cups are threaded onto the rod body  52  to compress the first  58  and second  60  elastomeric components directly against the bracket flange  68 . Nuts  66  are used to hold the first  62  and second  64  rigid cups in place.  
         [0032]     The combination of the first  58  and second  60  elastomeric components, and the first  62  and second  64  rigid cups cooperate with the bracket flange  68  to allow relative movement in up to ten degrees of freedom. Thus, the rod body  52  can rotate, twist, and move axially relative to the vehicle  26  and axle  24  brackets.  
         [0033]     Further, the vehicle  26  and axle  24  brackets are significantly simplified compared to traditional torque rod mounts. One example of this simplified bracket configuration is shown in greater detail in  FIGS. 5-6 . The vehicle bracket  26  includes a first flat portion  70  that attaches to the vehicle frame and a second flat portion  72  that receives the upper  30   a  and lower  30   b  pogo rods. The first  70  and second  72  flat portions are preferably orientated in the shape of an L.  
         [0034]     The axle bracket  24  includes a first flat portion  76  that mounts to the axle  10  and a second flat portion  78  that receives the upper  30   a  and lower  30   b  pogo rods. The first  76  and second  78  flat portions are preferably orientated in the shape of a T.  
         [0035]     For both second flat portions  72 ,  78 , only two (2) openings  80  are required to be formed in the respective vehicle  26  and axle  24  bracket, as shown in  FIG. 6 . This greatly simplifies manufacturing of the vehicle  26  and axle  24  brackets. The vehicle  26  and axle  24  brackets can easily be made by stamping, casting, or any other manufacturing process, and require minimal final machining.  
         [0036]     Another example configuration is shown in  FIG. 7 . In this example, the axle  10  is a tubular axle  82  with an axle bracket  84  that is directly welded to the tubular axle  82 . A vehicle bracket  86 , similar to vehicle bracket  26  is mounted to the vehicle frame. Upper  30   a  and lower  30   b  pogo rods extend between the vehicle bracket  86  and axle bracket  84  in a manner similar to that shown in  FIGS. 2 and 5 . Upper  30   a  and lower  30   b  pogo rods are positioned at each end of the tubular axle  82  as shown in  FIG. 1 .  
         [0037]     By welding the axle bracket  84  to the tubular axle  82 , traditionally used U-bolt attachments are eliminated, which results in weight and cost savings. Further, no re-torque is required, which reduces maintenance.  
         [0038]     Another example of a five (5) pogo rod configuration, similar to that of  FIG. 1 , is shown in  FIG. 8 . This configuration includes both a stabilizer bar  48  and a transverse pogo rod  32 . Upper  30   a  and lower  30   b  pogo rods (only the upper pogo rods  30   a  are visible) extend between vehicle  26  and axle  24  brackets at each end of the axle  10 . Although not clear from this view, upper pogo rods  30   a  are mounted vertically above lower pogo rods  30   b , i.e., the lower pogo rods  30   b  are directly underneath the upper pogo rods  30   a  shown in  FIG. 8 . A fifth pogo rod, i.e. the transverse pogo rod  32  extends from an axle bracket  34  at one axle end to a vehicle bracket  36  at an opposite axle end. The transverse pogo rod  32  is preferably positioned on one longitudinal side of the air springs  46  ( FIG. 9 ) while the stabilizer bar  48  is positioned on an opposite longitudinal side of the air springs  46  ( FIG. 12 ).  
         [0039]     The fifth pogo rod could be eliminated by orientating either of the upper  30   a  and lower  30   b  pogo rods at each end of the axle  10  in a V-shaped configuration. The upper pogo rods  30   a  would form an upper V-shape, and the lower pogo rods  30   b  would form a lower V-shape. Apexes of the upper and lower V-shapes would be positioned at the axle  10 .  
         [0040]      FIG. 10  shows an alternate configuration for a transverse pogo rod  90  for a drive axle  92 . In this configuration, one end  94  of the transverse pogo rod  90  is mounted to a bracket  96  at a carrier portion  98  of the drive axle  92 , and an opposite rod end  100  is mounted to a bracket  102  fixed to the vehicle frame  18 . The carrier portion  98  is preferably located near a center of the drive axle  92 , thus the transverse pogo rod  90  is generally shorter in length compared to the configuration shown in  FIGS. 8 and 9 .  
         [0041]     Pogo rods  30  can also be used for a linkage assembly for the stabilizer bar  48  as shown in  FIGS. 11-12 . A vehicle bracket  108  is mounted to the vehicle frame  18  at each end of the stabilizer bar  48 . A pogo link rod  110  is mounted to each stabilizer bar end and an associated vehicle bracket  108  as shown in  FIG. 12  (only one end is shown in  FIG. 12 , however the opposite end has a similar connection).  
         [0042]     The stabilizer bar  48  is also connected to the axle  10  as shown  FIG. 11 . The axle  10  includes a bracket  112  that supports a clamp  114  that surrounds a middle portion of the stabilizer bar  48 , as shown in  FIG. 12 .  
         [0043]     As shown in  FIG. 12 , the pogo link rod  110  includes first  62  and second  64  rigid cups that compress first  58  and second  60  elastomeric components directly against bracket  108  in manner similar to that shown in  FIG. 4 . As can be appreciated, the rod is much shorter in this embodiment than in the prior embodiments.  
         [0044]     Another suspension embodiment is shown in  FIGS. 13 and 14 . In this configuration, a mechanical suspension  120  includes a plurality of leaf springs  122  that extend between first  124  and second  126  brackets. The leaf springs  122  extend transversely relative to axle  10 . Pogo rods  30  used in this configuration need to clear the leaf springs  122  and thus are positioned outboard of the leaf springs  122  as shown in  FIG. 14 .  
         [0045]      FIG. 15  shows one example shock system  130  that can be incorporated into any of the vehicle suspensions described above. The shock system  130  includes a shock absorber  132  that works in conjunction with the air spring  46  to absorb road load inputs. The shock absorber  132  is mounted to an axle bracket  134  at one end, and is mounted to a vehicle bracket  136  at an opposite end.  
         [0046]     The subject invention provides a suspension system that is lighter and more cost effective than traditional trailing arm front air suspensions. Pogo rods are used as a linkage control to replace traditional torque rods. This significantly reduces system cost and the associated brackets are drastically simplified with regard to design and fastener requirements.  
         [0047]     A standard five (5) pogo rod configuration provides two upper trailing arms, two lower trailing arms, and a transverse arm. As discussed above, the transverse arm could be removed by mounting the upper trailing arms in a first V, and mounting the lower trailing arms in a second V, to absorb transverse loads in addition to fore-and-aft loadings. Sway is controlled by using smaller pogo rods as the linkage for the stabilizer bar.  
         [0048]     The bracket designs at both the vehicle frame and axle are simplified as only one hole is required for attaching each pogo rod end. The hole has the same size for all attachments. This eliminates bosses and fasteners traditionally needed to attach a typical straddle mount torque rod.  
         [0049]     The subject invention can be used for many different axles including an I-beam front axle, a tubular box section front axle, or any truck or trailer rear axle such as a tag axle, pusher axle, drive axle, etc. Further, by having the upper and lower pogo rods parallel to each other, brake dive, i.e. steering effect, issues are reduced. These issues can be a problem for a leaf spring or traditional trailing arm suspension.  
         [0050]     Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.