Abstract:
A collision energy absorption apparatus and a vehicle front end structure including the apparatus. The apparatus is welded to a bumper beam and is laterally adjacent a longitudinally extending member disposed behind the bumper beam. The apparatus has a central body having a front edge attached to the bumper beam and a rear edge that is spaced from the bumper beam and the longitudinally extending member. Upper and lower triangular walls extend between the central body and the longitudinally extending member. A rib extends laterally outwardly from the central body.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to an energy absorbing apparatus for a vehicle that is involved in a small offset rigid barrier frontal collision. 
       BACKGROUND 
       [0002]    Land vehicles are tested for crashworthiness by a variety of tests including frontal impacts, side impacts, rear impacts, roll-over and other tests. Frontal impact tests were previously developed that specified that a vehicle impacts a barrier between the frame rails that extend longitudinally relative to the vehicle. In this type of test, the frame rails provide the primary support for the vehicle body and reduce any potential for intrusions into the passenger compartment. The extent of any intrusions into the passenger compartment are measured at the brake pedal, foot rest, left toe pan, center toe pan, right toe pan, left instrument panel, right instrument panel, and door. 
         [0003]    A new test is proposed for simulating small offset frontal collisions against a rigid barrier. In the proposed test, the vehicle impacts a rigid barrier having a six inch pole-like radius on one corner with a 25% overlap at 40 MPH. The impact is outboard of the frame rails so that the frame rails do not provide as much resistance to intrusion into the passenger compartment as in the case of impacts between the frame rails. 
         [0004]    The weight of land vehicles is being substantially reduced to improve fuel efficiency. Vehicles are currently being designed to reduce the weight of the vehicle with a parallel objective of not compromising performance or crashworthiness. It is difficult to meet the proposed test requirements for the small offset rigid barrier crash test while reducing vehicle weight and reducing manufacturing costs. 
         [0005]    The above problems and other problems are addressed by this disclosure as will be summarized below. 
       SUMMARY 
       [0006]    According to one aspect of this disclosure, an energy absorbing apparatus comprising an attachment to an energy absorbing assembly is disclosed for a vehicle having a bumper rail. The apparatus includes a central body that is planar in shape and is attached to the bumper rail with a leading edge of the central body contacting the bumper rail and a trailing edge of the central body being spaced from the bumper rail. A first wall extends from a first edge of the central body to a longitudinally extending structural member backing the bumper rail. A second wall extends from a second edge of the central body to the longitudinally extending structural member backing the bumper rail. A rib extends from the central body away from the structural member. 
         [0007]    According to other aspects of this disclosure relating to the apparatus, the rib may be widest adjacent the leading edge and is narrowest at the trailing edge. The first and second walls may be narrowest adjacent the leading edge and are widest at the trailing edge. The longitudinally extending structural member may be a crush can disposed rearward of the bumper rail and forward of a frame rail of the vehicle. The rib may be a roll bonded double thickness of a sheet of metal that is welded or otherwise attached to extend from the central body. The rib may have a trapezoidal shape. The first wall and second wall may be triangular. A force from a collision of the vehicle with an object disposed outboard of the longitudinally extending structural member is applied to the rib, then to the central body, then to the first leg and the second leg, and then to the longitudinally extending structural member. 
         [0008]    According to another aspect of this disclosure, a collision absorbing assembly is disclosed for a land vehicle. The land vehicle comprises a bumper beam disposed at the front end of the vehicle, one or more crush cans are disposed rearward of the bumper beam, and a frame assembly of the vehicle disposed rearward of the crush cans. An impact absorbing attachment is attached to the bumper beam and contacts a lateral side of one of the crush cans. The impact absorbing apparatus includes a central body that is planar in shape and attached to the bumper beam with a leading edge of the central body contacting the bumper beam and a trailing edge of the central body being spaced from the bumper beam. A first wall and a second wall extend from a first and a second edge of the central body, respectively, and to one of the crush cans. A rib is attached to the central body to extend from the central body away from the one crush can. 
         [0009]    According to other aspects of this disclosure relating to the collision absorbing assembly, a bracket may be disposed between the frame assembly and the crush cans and the trailing edge of the central body is spaced from the bracket. The collision absorbing attachment may be welded to the bumper beam and may contact the front end of the crush can adjacent the bumper beam, but is not otherwise attached to the crush can. 
         [0010]    The above aspects and other aspects of this disclosure will be described in greater detail below with reference to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a fragmentary perspective view of a vehicle front end showing an example of a collision energy absorption apparatus. 
           [0012]      FIG. 2  is a fragmentary side elevation view of the vehicle front end and collision energy absorption apparatus illustrated in  FIG. 1 . 
           [0013]      FIG. 3  is a side/rear perspective view of the collision energy absorption apparatus illustrated in  FIG. 1 . 
           [0014]      FIG. 4  is a fragmentary plan view of the vehicle front end and collision energy absorption apparatus illustrated in  FIG. 1 . 
           [0015]      FIG. 5  is a front elevation view of the collision energy absorption apparatus illustrated in  FIG. 1  attached to a crush can. 
           [0016]      FIG. 6  is a fragmentary cross-sectional view of the collision energy absorption apparatus attached to a crush can. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    A detailed description of the illustrated embodiments of the present invention is provided below. The disclosed embodiments are examples of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale. Some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed in this application are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art how to practice the invention. 
         [0018]    Referring to  FIGS. 1 and 2 , an energy absorbing apparatus  10  is disposed in the front end  12  of a vehicle  14  that is partially depicted. A bumper beam  16  is provided at the front end  12  of the vehicle  14 . A crush can  18  is assembled between the bumper beam  16  and a bracket  20 . The bracket  20  is interposed between the crush can  18  and a frame rail  24 . The energy absorbing apparatus  10  is welded to the bumper beam  16  and is spaced from the bracket  20 . The crush can  18  is designed to absorb energy in the event of a front end collision. The energy absorbing apparatus  10  provides additional protection against collision with the bumper beam  16  outboard of the frame rail  24 . 
         [0019]    Referring to  FIG. 3 , the structure of one embodiment of the energy absorbing apparatus  10  is described. The energy absorbing apparatus  10  includes a central body  28  that may be manufactured as a regular stamped part or may be formed by pressure roll bonding aluminum. The pressure bonded aluminum allows two thin aluminum sheets to be bonded together to add stiffness and achieve weight savings. The roll bonded, double thickness of aluminum sheet includes a plurality of circular indentations  30  that provide higher section stiffness and a higher buckling load. The higher buckling load allows the energy absorption apparatus  10  to withstand higher stresses and transfer higher crash loads to the main crush can  18  (shown in  FIGS. 1 and 2 ) prior to buckling. Each aluminum sheet may be about 1 mm thick and is mated by the indentations  30  to a mirror image sheet in the roll bonding process. 
         [0020]    The central body  28  has a leading edge  32  that is welded to the bumper  16  (shown in  FIGS. 1 and 2 ). The leading edge  32  of the energy absorbing apparatus  10  is also located adjacent to the crush can  18  (shown in  FIGS. 1 and 2 ). A trailing edge  34  of the energy absorbing apparatus  10  is spaced from the bumper beam  16  and also spaced from the crush can  18 . An upper edge  36 , or first edge, of the central body  28  extends from the leading edge  32  to the trailing edge  34 . A lower edge  38 , or second edge, of the central body  28  also extends from the leading edge  32  to the trailing edge  34 . A first wall  40 , or upper wall, and a second wall  42 , or lower wall, extend from the upper edge  36  and lower edge  38  of the central body  28 , respectively, to the crush can  18 . 
         [0021]    Referring to  FIGS. 3 and 4 , a lateral rib  44  that is wider at its front edge  46  adjacent to the bumper beam than at the rear edge  48  that is adjacent the trailing edge  34  of the central body  28 . The lateral rib  44  may be made with a pressure roll bond process in which two aluminum sheets are bonded together to provide greater stiffness and buckling resistance while being lighter in weight than a single thicker sheet of aluminum. The rib alternatively may be made in a conventional stamping operation. The lateral rib  44  may be welded or otherwise attached to the central portion  28 . The lateral rib  44  alternatively may be formed as a flange of the central portion  28 . 
         [0022]    Referring to  FIGS. 5 and 6 , a crush can  18  is illustrated that is a generally octagonal shaped member that extends longitudinally rearward of the bumper beam  16  (shown in  FIGS. 1 and 2 ). The energy absorbing apparatus  10  is shown to be retained in a spaced relationship relative to the crush can  18  by the first wall  40  and second wall  42 . The lateral rib  44  extends in the outboard direction and away from the crush can  18 . 
         [0023]    In the event of a collision with an object outboard of the frame rail  24  (shown in  FIGS. 1 ,  2  and  4 ), the bumper beam  16  is initially contacted and driven into the front edge  46  of the rib  44 . The rib transfers a portion of the energy from the impact to the central portion  28  and is driven toward the side of the crush can  18 . The first wall  40  and second wall  42  spread apart as the central portion  28  is driven toward the crush can  18 . The central portion  28  is driven into engagement with the crush can  18  and applies a lateral load to the crush can  18  driving the crush can  18  inboard and absorbing a portion of the collision energy. The walls  40 ,  42  are spread apart as the central portion  28  is flattened against the crush can  18 . The crush can  18  is connected to the bracket  20 . The bracket  20  is connected to the frame rail  24  so that energy initially exerted outboard of the frame rail  24  is redirected by the energy absorbing apparatus  10 , to the crush can  18 , the bracket  20 , and frame rail  24 . 
         [0024]    While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosed apparatus and method. 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 disclosure as claimed. The features of various implementing embodiments may be combined to form further embodiments of the disclosed concepts.