Abstract:
An energy absorbing assembly for a vehicle that has a bumper and a frame. A receptacle is defined within the frame. A collapsible member is provided between the bumper and a recessed location spaced away from the bumper in the receptacle. The collapsible member may collapse at least partially into the receptacle in the event of a collision.

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a kinetic energy absorbing rail and attachment bracket assembly. 
     2. Background Art 
     Vehicles are designed to manage kinetic energy to protect vehicle occupants in the event of a collision. Frame members and frame rails are used to provide a protective cage around the passenger compartment. Telescopically collapsible rails are used to absorb kinetic energy in predetermined locations so that less energy is required to be absorbed in the mid-body portions of the vehicle. 
     Preferential crush zones are generally provided inboard of a front bumper and may also be provided inboard of a rear bumper. Normally, only a limited amount of space is available in a vehicle design to provide for crush zones. Conventional telescopically collapsible rails may collapse to between 20-30% of their over all length in a collision having sufficient force to require the rails to fully collapse. As a result, only 70-80% of the space in a preferential crush zone is available for absorbing kinetic energy in a collision. 
     To the extent that more energy can be managed in the preferential crush zones, less energy load is applied to the mid-body portions of the vehicle. Vehicle mass can be reduced and fuel efficiency can be improved to the extent that more energy is absorbed by the telescopically collapsible rails. The additional energy absorbed by the collapsible rails results in less energy being applied to the mid-body portions of the vehicle. 
     This application discloses and claims an apparatus that is directed to the above problems and limitations of the prior art. 
     SUMMARY 
     According to one aspect of this application, an energy absorbing assembly is provided for a vehicle that has a bumper and a frame. The assembly comprises a receptacle defined within the frame that extends through an outer end of the frame. A collapsible member is located between the bumper and a recessed location within the receptacle. The collapsible member may collapse at least partially into the receptacle in the event of a collision. 
     According to others aspects of this application, the collapsible member may collapse completely into the receptacle in the event of a collision. A bracket of the frame may define the receptacle and kinetic energy may be absorbed by the collapsible member until the collapsible member is completely received in the receptacle. 
     The receptacle may be part of a bracket that defines by a hollow cylindrical portion that has an inner diameter dimension. The telescopically collapsing member may have a maximum diameter section that is cylindrical and has an outer diameter that is less than the inner diameter of the hollow cylindrical part of the bracket. A longitudinally outer portion of the maximum diameter section of the telescopically collapsing member may be attached to the outer end of the frame and a longitudinally inboard portion of the maximum diameter section may be attached to an inboard side of the hollow cylindrical part of the bracket. 
     An extended portion of the telescopically collapsing member may be disposed forward of the maximum diameter section may include a plurality of sections that are of decreasing diameter progressively from the maximum diameter section to the bumper. Each of the plurality of sections is intended to collapse into the next greater diameter section. 
     According to another aspect of this application, a frame for a vehicle is provided with an energy absorbing telescopically collapsing member. The frame comprises a bracket disposed at an outer end of the frame that defines an opening that extends from the outer end of the frame to a location spaced inboard of the outer end of the frame. The telescopically collapsing member is received within the opening with a first end that is proximate a bumper of the vehicle and a second end that is disposed at least partially inboard of the outer end of the frame. 
     According to further aspects of the frame for the vehicle, the opening in the bracket provides clearance for the telescopically collapsing member to collapse fully or partially behind the outer end of the frame and into the opening. The opening in the bracket may be defined by a hollow cylindrical part of the bracket that has an inner diameter dimension. The telescopically collapsing member may also be cylindrical and the maximum diameter section may have an outer diameter that is less than the inner diameter of the hollow cylindrical part of the bracket. 
     The second end of the telescopically collapsing member may be welded to the location spaced inboard of the outer end of the frame. The telescopically collapsing member may also be welded to the bracket at the outer end of the frame. The location where the second end is welded to the frame may be disposed at the opposite end of the opening in the bracket from the outer end of the frame. The bracket may be one that extends in a vertical direction and is secured to a lower frame member and to an upper frame rail. 
     These and other aspects of this application will be better understood and more fully described with reference to the attached drawings below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of the front frame of a vehicle that is provided with a bracket and telescopically collapsible member; 
         FIG. 2  is a fragmentary longitudinal cross-section view of the bracket and telescopically collapsible member illustrated in  FIG. 1 ; 
         FIG. 3  is a lateral cross-section view taken along the line  3 - 3  in  FIG. 2 ; 
         FIG. 4  is a diagrammatic fragmentary cross-sectional view showing the telescopically collapsible member beginning to collapse; 
         FIG. 5  is a diagrammatic fragmentary cross-sectional view showing the telescopically collapsible member nearly fully collapsed into the opening defined by the bracket; 
         FIG. 6  is a lateral cross-section view of a square or rectilinear embodiment of the receptacle in the telescopically collapsible tube made according to an alternative embodiment of the disclosure; 
         FIG. 7  is a lateral cross-section view of a hexagonal embodiment of the receptacle in the telescopically collapsible tube made according to an alternative embodiment of the disclosure; and 
         FIG. 8  is a cross-section view of an octagonal embodiment of the receptacle in the telescopically collapsible tube made according to an alternative embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an energy absorbing assembly generally identified by reference numeral  10  is shown in conjunction with a vehicle generally indicated by reference numeral  12 . A portion of the vehicle illustrated in  FIG. 1  is a front frame assembly generally indicated by reference numeral  14 . A front bumper  16  is provided, but it should be understood that the invention is equally applicable to rear bumpers. The front frame assembly  14  includes an upper frame rail  18  and a sub-frame  20 . A bracket  24  is connected to and extends between the upper frame rail  18  and the sub-frame  20 . 
     A telescopically collapsing member  26  is disposed between the bumper  16  and the upper frame rail  18  and forms part of the front frame assembly  14 . The bracket  24  includes a receptacle  28  that comprises a cylindrical tubular end of the bracket  24 . The telescopically collapsing member is received within the receptacle  28 . 
     Referring to  FIG. 2 , the bracket  24  is shown with the telescopically collapsing member  26  being received within the receptacle  28 . The telescopically collapsing member  26  includes a lead section  30  that has a minimum diameter and a plurality of intermediate sections  32  that are of increasing diameter compared to the lead section  30  and the next adjacent section. A receiving section  36  is the section of the collapsing member  26  that has the maximum diameter. The receiving section  36  is assembled within the receptacle  28  of the bracket  24 . 
     Referring to  FIG. 3 , the telescopically collapsing member  26  is shown in a cross-section taken through the telescopically collapsing member  26  toward the receptacle  28 . The telescopically collapsing member  26  and the receptacle  28  shown in  FIG. 3  are cylindrical in shape. It is possible to practice the invention using other shapes, such as those shown and described with reference to  FIGS. 6-8 . Three outer end welds  40  are shown that secure the collapsing member  26  to the receptacle  28  at spaced locations at the front end of the front frame assembly  14 . The welds  40  could be MIG welds, resistance welds, laser welds, or the like. 
     Referring to  FIG. 2 , inboard welds  42  are provided to join the receptacle  28  to the maximum diameter section or receiving section  36  of the collapsing member  26  on the opposite side of the receptacle  28  from the outer end welds  40 . The receiving section  36  is at least tack welded and potentially more fully welded to both ends of the receptacle  28 . 
     Referring to  FIG. 4 , the collapsible member  26  is shown at a point in a collision where an impact indicated by the phantom arrow at the left side of  FIG. 4  is applying a load to the end of the lead section  30 . The lead section  30  is shown collapsing into the next adjacent intermediate section  32 . The collapsing tube forms two reversely turned parts of the collapsing member  26 . This process of collapsing sequentially into the other intermediate section may continue if the load continues to be applied to the lead section  30 . If only a minor impact is imparted, the extent to which the tube collapses may be at the point shown at  FIG. 4  or later depending upon the amount of load applied. 
     Referring to  FIG. 5 , the telescopically collapsing member  26  is shown nearly fully collapsed into the receptacle  28 . The receptacle is shown with the receiving section  36  in the same position as shown in  FIG. 2 . However, it should be understood that depending upon the dynamics and kinetic energy applied some distortion of the receiving section  36  and receptacle may occur. However, as shown in  FIG. 5 , the lead section  30  is collapsed to a point just outside of the receptacle  28  and the intermediate sections  32  are collapsed upon themselves. The collapsing of the telescopically collapsing member  26  may continue until the collapsing member  26  is fully received in the receptacle  28 . At this point, the telescopically collapsing member  26  is collapsed to provide a zero stack up relative to the outer end of the frame. The outer end of the frame is defined as being the end of the receptacle  28  closest to the bumper  16 . 
     Referring to  FIG. 6 , an alternative embodiment is shown in which a square receptacle  44  receives a square collapsing member  46 . This embodiment is the least efficient embodiment in terms of kinetic energy absorbed per cross sectional area of telescopically collapsing tube. The most efficient embodiment is illustrated in  FIGS. 1-5 . 
     Referring to  FIG. 7 , a hexagonal receptacle  48  is shown with a hexagonal collapsing member  50 . This embodiment is more efficient than an embodiment of  FIG. 6  in terms of kinetic energy absorbed upon complete collapse into the receptacle  48  per cross-sectional area of the collapsing member  50 . 
     Referring to  FIG. 8 , an octagonal receptacle  52  is shown with an octagonal collapsing member  54 . This embodiment approaches the efficiency of the embodiment of  FIGS. 1-5  in terms of kinetic energy absorbed per cross sectional area of collapsing member  54 . 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.