Patent Publication Number: US-2021172491-A1

Title: Vulcanized support ring for hybrid air spring bellow

Description:
TECHNICAL FIELD 
     The present disclosure relates to air spring assemblies for a vehicles with a hybrid bellow configuration. 
     BACKGROUND 
     An air spring assembly for a motor vehicle includes a bellow filled with air to support the vehicle and absorb road inconsistencies. A hybrid bellow includes an outer support ring that is crimped to an inner support ring to provide a “B” shape in the bellow. The inner and outer support rings can complicate assembly and manufacture. 
     SUMMARY 
     An air spring assembly according to a non-limiting exemplary embodiment includes, among other possible things, a bellow including an outer surface, a first end and a second end, wherein the bellow comprises a rubber material that is expandable to an inflated diameter and an outer ring disposed on the outer surface of the bellow between the first end and the second end, the outer ring containing an embedded cord to define a constrained portion of the bellow between expanded portions to establish a “B” fold in the bellow. 
     In another disclosed embodiment of the foregoing air spring assembly, the outer ring comprises a rubber material containing the cord. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the cord comprises at least one synthetic fiber cord. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the outer ring includes at least one synthetic fiber cord that is vulcanized onto the bellow. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the bellow comprises a first elasticity and the outer ring comprises a second elasticity that is less than the first elasticity. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the constrained portion comprises a constrained diameter that is less than the inflated diameter. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the outer ring comprises a rubber strip surrounding the cord that is vulcanized to the outer surface of the bellow. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the cord comprises a woven bundle of cords. 
     In another disclosed embodiment of any of the foregoing air spring assemblies, the bellow and outer ring comprise a single unitary part. 
     A method of forming a bellow for an air spring assembly according to another non-limiting exemplary embodiment of this disclosure includes, among other possible things, forming a bellow from a rubber material to include an outer surface, a first end and a second end, wrapping a cord around a portion of the bellow and encasing the cord in a rubber material to affix the cord to the outer surface of the bellow in a vulcanization process. 
     In another disclosed embodiment of the foregoing method, including forming an outer ring of rubber material around the cord such that the cord is embedded within the outer ring. 
     In another disclosed embodiment of any of the foregoing methods, the cord comprises at least one synthetic fiber cord. 
     In another disclosed embodiment of any of the foregoing methods, the cord comprises a woven bundle of cords. 
     In another disclosed embodiment of any of the foregoing methods, the cord includes an elasticity that is less than an elasticity of the rubber material forming the bellow to define a constrained portion of the bellow between expandable portions to establish a “B” fold in the completed bellow. 
     In another disclosed embodiment of any of the foregoing methods, the constrained portion comprises a constrained diameter that is less than expandable portions. 
     In another disclosed embodiment of any of the foregoing methods, wrapping the cord includes wrapping the cord with a rubber strip and vulcanizing the rubber strip to the outer surface of the bellow to encase the cord. 
     Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
     These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a portion of an example air spring assembly embodiment. 
         FIG. 2  is a schematic view of an enlarged portion of the example air spring assembly. 
         FIG. 3  is a sectional view of a portion of an example outer ring embodiment. 
         FIG. 4  is a top view of an example cord assembly of the outer ring. 
         FIG. 5  is a cross-section of another example outer ring embodiment. 
         FIG. 6  is a cross-section of yet another example outer ring embodiment. 
         FIG. 7  is a schematic view of an example method for forming a bellow. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an example air spring assembly  10  includes a bellow  12  with a “B” shaped fold  18 . The “B” shaped fold  18  is disposed between a first end  14  and a second end  16  of the bellow  12 . The “B” shaped fold provides a desired suspension that decouples torsion and kinematics of the air spring assembly  10 . The “B” shaped fold  18  is defined by a constrained portion  22  disposed between expanded regions  28 . The constrained portion  22  is formed by an outer ring  24  disposed about an outer surface  30  of the bellow  12 . The bellow  10  expands to an inflated diameter  20  within the expanded regions  28 . The constrained portion  22  is held at a diameter  26  that is less than the inflated diameter  20 . 
     Referring to  FIG. 2 , with continued reference to  FIG. 1 , the outer ring  24  includes at least one cord  32  encapsulated within a rubber material  34 . In one disclosed example embodiment, the rubber material  34  of the outer ring  24  is the same as is utilized to form the bellow  12 . The cord  32  includes an elasticity that is much less than that of the bellow  12  to constrain expansion beyond the diameter  26  in the constrained region. 
     Referring to  FIGS. 3 and 4 , with continued reference to  FIG. 2 , the disclosed example outer ring  24  includes cords  32  in a woven configuration that extend about a circumference of the outer ring  24 . The example cords  32  are formed from a synthetic material with a limited capacity to expand relative to the rubber material forming the bellow  12 . The synthetic material may include any synthetic material that is compatible with the rubber material and has limited elasticity. The cords  32  may be formed as a loop of many cords attached to each other to define the desired diameter of the constrained portion  22 . In the disclosed example, the woven cords  32  define a maximum diameter  35  ( FIG. 4 ). 
     Referring to  FIG. 5 , another example outer ring embodiment is schematically shown and indicated at  36 . The example outer ring  36  includes a single cord  32  that is encapsulated in the rubber material  34 . 
     Referring to  FIG. 6 , another example outer ring embodiment is schematically shown and indicated at  38 . The example outer ring  38  includes several cords  32  that are also encapsulated within a rubber material  34 . It should be appreciated that although several outer ring embodiments are shown by way of example, that other configurations, numbers and shapes of cords  32  can be utilized within the scope and contemplation of this disclosure. 
     Referring to  FIG. 7 , an example method of forming a bellow for an air spring is schematically shown and indicated at  40 . The example method includes forming a bellow  45  of a rubber material  42 . In this example, the rubber material  42  is in a pre-vulcanization state. Vulcanization is a known process utilized to treat the rubber material  42  to increase durability and flexibility. The example method forms the outer ring  24  during the vulcanization process to provide a single integral bellow  12  with the outer ring  24 . A single cord or a plurality of cords  44  are installed and positioned onto the bellow  45  and surrounded by a rubber strip  46 . The cords  44  may be wrapped or slid over the outside of the bellow  45 . 
     The bellow  45  with the cords  44  and the rubber strip  46  are then placed within a tool  48  for vulcanization. The tool  48  may apply pressure to bond the rubber strip  46  over the cords  44  and to the bellow  45 . During vulcanization, the rubber strip  44  encapsulates the cords  44  and affixes to the outer surface of the bellow  45 . The vulcanization tool  48  and process are disclosed by way of example. Any known vulcanization process may be utilized and are within the scope and contemplation of this disclosure. 
     The completed bellow  12  is removes from the vulcanization tool  48  and includes the outer ring  24 . The outer ring  24  becomes an integral part of the completed bellow  12  and constrains a portion of the bellow  12  to define the desired “B” shaped fold  18  when inflated during operation and use of the air spring  10 . 
     Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure.