Patent Publication Number: US-2022212616-A1

Title: Beam for front bumper assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63/133,937, filed Jan. 5, 2021, the disclosure of this prior application is considered part of this application and is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to bumper assemblies for vehicles, and more particularly to a bumper beam or a reinforcement beam spanning across a front end of a vehicle. 
     BACKGROUND 
     When a vehicle undergoes impact from a crash at the front end of the vehicle, the vehicle&#39;s bumper assembly is designed to receive and absorb the impact energy in an effort to mitigate damage to the surrounding vehicle structure and prevent injury to people in the occupant cabin of the vehicle. In addition, it is beneficial for a bumper assembly to avoid harmful damage to the other vehicle involved in a collision. For example, some vehicle impact tests that are mandated by government regulations and insurance certifications measure the resulting damage to a standardized barrier designed to mimic the other vehicle during a frontal impact collision, such as a movable progressive deformable barrier (MPDB) test or a Small Overlap Rigid Barrier (SORB) test. The results of these tests may be dependent on various vehicle components and designs, including the ability of the vehicle bumper to disperse impact deformation over specified sections of a barrier. 
     A common issue encountered by vehicles subjected to frontal impact tests that involve a barrier overlapping a corner of the vehicle is that the ends of the reinforcement beam often have a sharp corner that becomes more pronounced when the center of the reinforcement beam collapses inward. The sharp corner is formed by the end of the reinforcement beam, which terminates near its connection with the crush cans. This sharp corner can pierce into an impact barrier and reduce the area of the bumper assembly that effectively absorbs impact energy. Reinforcement beams have generally not been extended to address this issue due to the added mass and inability to fit such an extension in the available package space. Alternatively, corner brackets and other accessories have been developed to mount to the ends of reinforcement beam, each of which add significant cost and manufacturing complexities. 
     SUMMARY 
     The present disclosure provides a reinforcement beam for a front vehicle bumper assembly that has discrete bends at outboard sections of the beam to allow ends of the beam to extend rearward and outward beyond its crush can connections to outboard portions of the bumper assembly that assist with dispersing impact energy during overlapping frontal impact collisions. The discrete bends provide a degree of curvature at the outboard sections of the reinforcement beam to extend the ends outward and rearward, while maintaining a relatively straight or slightly curved center section of the beam between the crush cans. In some examples, the reinforcement beam is formed with a high strength martensitic steel of at least 980 MPa, such as at least 1,500 MPa. Also, the reinforcement beam may be roll formed to have at least two hollow areas extending continuously along its length. The shape and material of the reinforcement beam together are configured to prevent a large buckling at the center section during a frontal impact, which maintains the position of outboard ends of the beam to absorb impact energy at the outboard area of the vehicle. 
     According to one aspect of the present disclosure, a reinforcement beam for a vehicle bumper assembly includes a metal sheet formed into a beam having at least one tubular section extending along a length of the beam. The length of the beam has a central section disposed between end sections of the beam, such that the length of the beam spans laterally across a vehicle frame. The beam also has bend sections formed between the central section and the end sections of the beam to dispose the end sections rearward from the central section relative to the vehicle frame. The end sections of the beam terminate at distal ends an extended length outboard along the length of the beam from the pair of connection features configured to attach the beam to crush cans. In some implementations, the extended length is at least 200 mm, and in some examples is greater than 150 mm and/or at least ⅙ of the length of the beam. 
     Implementations of the disclosure may include one or more of the following optional features. In some implementations, the beam includes two tubular sections that extend in parallel along the beam, such as at least along the central section of the beam. For example, the two tubular sections may be separated from each other along the length of the beam. In another example, the two tubular sections share a common center wall along the length of the beam. 
     In some implementations, the bend sections each have a bend radius of less than 1,000 mm. Also, in some implementations, the bend radius of each of the bend sections is less than half of the length of the reinforcement beam between the distal ends along the longitudinal axis of the reinforcement beam. The end sections of the beam, in some examples, include straight sections that extend to the distal ends of the beam. The straight sections may each having a length of greater than 100 mm. In some examples, the central section of the beam is straight along the length of the beam. Further, in some implementations, the bend sections of the beam have transition sections at ends of the bend sections that interface with the central and end sections of the beam. The transitions sections each having a progressively decreasing bend radius from the central section or the end section to the bend radius at the bend section, such as less than 1,000 mm. The transition sections, in some examples, have a length of at least 50 mm. 
     According to another aspect of the present disclosure, a vehicle bumper assembly includes a reinforcement beam and a pair of crush cans. The reinforcement beam is formed from a metal sheet and includes at least one tubular section that extends along a length of the reinforcement beam. The length of the reinforcement beam has a central section disposed between end sections with bend sections disposed between the central section and end sections. The length of the reinforcement beam is configured to span laterally across a vehicle frame with the end sections extending rearward from the central section relative to the vehicle frame. The pair of crush cans have rear portions that attach to the vehicle frame and front portions that attach to the reinforcement beam at least partially at the bend sections. The end sections of the reinforcement beam terminate at distal ends that are located rearward from the rear portions of the pair of crush cans relative to the vehicle frame. 
     In further implementations, the distal ends of the reinforcement beam are disposed at least 200 mm outboard along the length of the reinforcement beam from the front portions of the pair of crush cans. The pair of crush cans, in some examples, have a length between end surfaces of the front and rear portions of at least 150 mm. In some implementations, the pair of crush cans each have a tubular can portion that is attached to the reinforcement beam via a frame connection plate, where the tubular can portions extend generally longitudinally relative to the vehicle frame. 
     According to a further aspect of the disclosure, a vehicle bumper assembly includes a reinforcement beam that is formed from a metal sheet and has at least one tubular section extending along a length of the reinforcement beam. The length has a central section disposed between end sections with bend sections disposed between the central section and end sections. The length is configured to span laterally across a vehicle frame with the end sections extending rearward from the central section relative to the vehicle frame. A pair of crush cans have rear portions that are configured to attach to the vehicle frame and front portions that attach to a rear surface of the reinforcement beam. The end sections of the reinforcement beam terminate at distal ends of the reinforcement beam that are disposed an extended length outboard along the length of the beam from the front portions of the pair of crush cans. The extended length is at least 200 mm of the length of the reinforcement beam. 
     The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, advantages, purposes, and features will be apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side elevation view of a vehicle having a bumper assembly. 
         FIG. 2  is a top plan view of a vehicle and a trolley used in an MPDB impact test. 
         FIG. 3  is a front elevation view of an example of a bumper assembly. 
         FIG. 4  is an upper perspective view of the bumper assembly shown in  FIG. 3 . 
         FIG. 5  is a front upper perspective view of the crush cans and reinforcement beam of the bumper assembly shown in  FIG. 4 . 
         FIG. 6  is a rear upper perspective view of the bumper assembly shown in  FIG. 5 . 
         FIG. 6A  is a cross-sectional perspective view of the bumper assembly taken at the section line A-A shown in  FIG. 6 . 
         FIG. 6B  is a cross-section view of the reinforcement beam taken at the section line B-B shown in  FIG. 5 . 
         FIG. 7  is a rear perspective view of the reinforcement beam shown in  FIG. 4 . 
         FIG. 8  is a top plan view of the crush cans and reinforcement beam of the bumper assembly shown in  FIG. 4 . 
         FIG. 9  is a side elevation view of the crush cans and reinforcement beam of the bumper assembly shown in  FIG. 4 . 
         FIG. 9A  is a cross-sectional elevation view of the bumper assembly taken at the section line A-A shown in  FIG. 6 . 
         FIG. 10  is a top plan view of the reinforcement beam shown in  FIG. 4 . 
         FIG. 11  is an upper perspective view of another example of a bumper assembly. 
         FIG. 12  is a rear perspective view of the bumper assembly shown in  FIG. 11 . 
         FIG. 12A  is a cross-sectional perspective view of the bumper assembly taken at the section line A-A shown in  FIG. 12 . 
         FIG. 12B  is a cross-section view of the reinforcement beam taken at the section line B-B shown in  FIG. 11 . 
         FIG. 13  is a top plan view of the crush cans and reinforcement beam of the bumper assembly shown in  FIG. 11 . 
         FIG. 14  is a side elevation view of the crush cans and reinforcement beam of the bumper assembly shown in  FIG. 11 . 
         FIG. 14A  is a cross-sectional elevation view of the bumper assembly taken at the section line A-A shown in  FIG. 12 . 
         FIG. 15  is a top plan view of the reinforcement beam shown in  FIG. 11 . 
         FIG. 16  is a front upper perspective view of a further example of a reinforcement beam. 
         FIG. 17  is a rear upper perspective view of the reinforcement beam shown in  FIG. 16 . 
         FIG. 17A  is a cross-sectional perspective view of the bumper assembly taken at the section line A-A shown in  FIG. 17 . 
         FIG. 18  is a top plan view of the reinforcement beam shown in  FIG. 16 . 
         FIG. 19  is schematic illustration of a bending process for a reinforcement beam. 
         FIG. 20  is a top plan view of an example of a reinforcement beam. 
         FIG. 21  is a top plan view of another example of a reinforcement beam. 
         FIG. 22  is a top plan view of the reinforcement beam of  FIG. 20  overlaying the reinforcement beam of  FIG. 21 . 
         FIG. 23  is a top plan view of a further example of a reinforcement beam. 
         FIG. 24  is a top plan view of the reinforcement beam shown in  FIG. 21 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings and the illustrative examples depicted therein, a bumper assembly  10  for a vehicle  12 , such as shown in  FIG. 1 , has a reinforcement beam  14 , also referred to as a bumper beam, that is supported by crush cans  16  that are attached to the reinforcement beam  14  at generally equal spacing from a center of the reinforcement beam  14 . The crush cans  16  of the bumper assembly  10  each mount to a frame member F, such as a frame rail or other portion of a conventional vehicle frame or a portion of uni-body frame or the like. The crush cans  16  support the reinforcement beam  14  to span laterally across a front end of the vehicle  12 , such as illustrated in  FIG. 1 . As further shown in  FIG. 1 , the front face of the reinforcement beam  14  is disposed in the package space available behind a front fascia  18  of the vehicle  12 . The bumper assembly  10  is mounted at the front end of the vehicle  12 , such as a car as shown in  FIG. 1  or other type of vehicle, such as a sport utility vehicle, truck, bus, van, or other type of motor vehicle. 
     As shown for example in  FIG. 2 , a mobile or movable progressive deformable barrier (MPDB) collision test includes a deformable barrier  20  that is attached to a trolley  22  directed to move toward and in general longitudinal alignment with the vehicle  12  for performing the MPDB collision test. The deformable barrier  20  is positioned to face the vehicle  12  and overlap with approximately 50% of the width of the vehicle  12 , such as to overlap an outboard area of the vehicle  12 . In the example shown in  FIG. 2 , the trolley  22  carrying the barrier  20  weighs approximately 1,400 kg and both the trolley  22  and the vehicle  12  are driven to a speed of about 50 kph immediately prior to collision. Upon impact with an object, such as the deformable barrier  20  of the MPDB collision test, the outboard portion of the bumper assembly  10  disclosed herein is configured to disperse the impact forces over the longitudinal extent of the reinforcement beam  14 , which extends outboard beyond the crush cans  16  to absorb the impact forces in an improved and more homogenous deformation from traditional bumper assemblies. The longitudinal shape and steel material of the reinforcement beam  14  together prevent a large buckling at the center section during a frontal impact, which maintains the position of outboard ends of the beam to absorb impact energy at the outboard area of the vehicle. 
     The bumper assembly  10  in some examples, such as shown in  FIGS. 3 and 4 , may also include a lower leg catcher beam  24  that spans laterally below the reinforcement beam  14 . The lower leg catcher beam  24  may be support by brackets  26  mounted to the reinforcement beam  14  and/or by reinforcement bars  28  that extend rearward from the lower leg catcher beam  24  connect to an underbody portion of the vehicle, such as a portion of the frame. The bumper assembly  10  may also include impact dispersion plates, such as the impact dispersion plates  30  shown in  FIGS. 3 and 4  connecting between the reinforcement beam  14  and the lower leg catcher beam  24  at the outboard portions of the bumper assembly  10 . In addition, the bumper assembly  10  shown in  FIGS. 3 and 4  includes suspender brackets  32  that connect between the distal ends of the reinforcement beam  14  and the lower leg catcher beam  24 . The bumper assembly in other examples may include other brackets or reinforcements from that shown in  FIGS. 3 and 4  or may otherwise omit or alter those shown, such as to conform the bumper assembly design to a particular vehicle design or package space. The lower leg catcher beam, brackets, and impact dispersion plates may be formed with various different materials and combinations of materials, such metal sheets, polymers, composites, and the like. The metals may be aluminum or steel alloys, such as a high-strength steel (e.g., a dual-phase steel) or ultra-high strength steel. 
     Referring now to the reinforcement beam  14  and crush cans  16  of the bumper assembly  10 , such as shown in  FIGS. 5 and 6 , the reinforcement beam  14  has discrete bends at outboard sections, such as bend sections  36 ,  38  shown in  FIG. 10 , of the reinforcement beam  14  for the ends of the reinforcement beam  14  to extend rearward and outward beyond the connections with the crush cans  16  to the outboard portions of the bumper assembly  10  that assist with dispersing impact energy during frontal impact collisions that overlap or otherwise contact the outer or corner sections of the front end of the vehicle. The discrete bends provide a degree of curvature at the outboard sections of the reinforcement beam  14  that causes the ends to extend outward and rearward relative to the vehicle  12 , while maintaining a relatively straight or slightly curved center section of the reinforcement beam  14  between the crush cans  16 . 
     As shown in  FIGS. 8 and 10 , the reinforcement beam  14  has a central section  34  that is disposed between end sections  40 ,  42  along the length of the reinforcement beam  14 . The reinforcement beam  14  also has bend sections  36 ,  38  disposed between the central section  34  and the end sections  40 ,  42  of the reinforcement beam  14  to position the end sections  40 ,  42  rearward from the central section  34  relative to the vehicle frame. The end sections  40 ,  42  of the reinforcement beam  14  terminate at distal ends  44 ,  46  that are an extended length outboard along the length of the reinforcement beam  14  from the connection between the beam  14  and the crush cans  16 . In some examples, the extended length outboard along the length of the reinforcement beam  14  is at least 200 mm. In addition or in other examples, the extended length outboard from the connection with the crush cans  16  is at least 100 mm, at least 300 mm, and/or approximately or at least ⅛ or at least ⅙ of the overall length of the reinforcement beam  14 . As shown in the example of  FIGS. 7 and 8 , the distal ends  44 ,  46  are disposed at an extended length  48  from the connection with the crush cans  16  of approximately 390 mm longitudinally along the center axis of the reinforcement beam  14 . As such, the extended length may be at least 200 mm, at least 300 mm, between 300 and 500 mm, and/or between 350 and 450 mm. 
     As further shown in  FIGS. 9 and 9A , the distal ends  44 ,  46  of the reinforcement beam  14  extend longitudinally rearward relative to the longitudinal extent of the vehicle frame at least a distance rearward the crush cans  16 . Specifically, the distal ends  44 ,  46  are shown extending rearward the frame engaging plate  66  of the crush cans  16  a distance  49  of approximately 70 mm or generally greater than ⅓ of the axial length of the corresponding crush can  16 , or generally greater than 50 mm. In additional examples, the rearward distance of the reinforcement beam  14  from the rear of the crush cans may be less within the scope of the disclosure, such as for bumper assemblies with crush cans that are relatively longer or that mount further outboard on the beam. 
     To provide the extended length of the reinforcement beam  14  rearward and outboard, the bend sections  36 ,  38  each have a bend radius of less than 1,000 mm, such as between 500 and 800 mm or between 450 and 600 mm. In some implementations, the bend radius of each of the bend sections  36 ,  38  is less than half of the length of the reinforcement beam  14  taken between the distal ends  44 ,  46  along the longitudinal axis of the reinforcement beam  14 . Such a tight bend radius is generally not achievable with a common roll forming sweep unit placed in-line with the end of a roll former and generally not achievable with high strength martensitic steel formed in a beam cross-sectional shape or profile, such as shown in  FIGS. 6-6B . To provide such a tight bend radius at each bend section, a straight beam may be placed through a 3D bend unit  70 , such as shown in  FIG. 19  and described further herein. 
     When formed with the tight bend radius, the upper and lower walls  58 ,  60  of the reinforcement beam  14  may include rippling disposed along the bend sections  36 ,  38 . The rippling may be formed with the 3D bend unit  70  to provide a generally consistent wave form that extends longitudinally along the length of the beam with the wave having a shorter wavelength closer to the rear wall  56  than the front wall  54 , where the wave is minimally present. The generally consistent wave form may be configured with wavelength and amplitude thresholds that do not diminish the capable impact load and energy absorption for the end sections of the beam  40 ,  42 . 
     As also shown in  FIGS. 8 and 10 , the end sections  40 ,  42 , of the reinforcement beam  14  include straight sections that extend to the distal ends  44 ,  46  of the reinforcement beam  14 . The straight sections may each having a length of 100 mm or a greater length, such that the straight sections may extend the entire length of the end sections  40 ,  42 . In some examples, the length of the straight sections may preferably be approximately 100 mm to 150 mm, or in other examples may be 80 mm to 200 mm or greater than 100 mm. Also, the central section  34  of the beam  14  may be generally straight or slightly curved, such as shown in  FIGS. 8 and 10  with the central section  34  having a radius of curvature of approximately 2,800 mm. Although shown in  FIGS. 8 and 10  with the end sections being linear straight sections, the end sections in additional examples may include or instead be slightly curved, such as the slight curvature of the central section. Thus, as shown in  FIG. 10 , the bend sections  36 ,  38  of the beam  14  may have transition sections  36   a ,  36   b ,  38   a ,  38   b  at ends of the bend sections  36 ,  38  that interface with the central section  34  and end sections  40 ,  42  of the reinforcement beam  14 . The transitions sections  36   a ,  36   b ,  38   a ,  38   b  each having a progressively decreasing bend radius from the central section  34  or the end section  40 ,  42  to the bend radius at the constant curvature of the bend sections  36 ,  38 . The transition sections may vary in length depending on the degree of curvature that is changing and whether the curvature is increase or decreasing. For example, the transition sections  36   a ,  36   b ,  38   a ,  38   b  have a length of at least 25 mm, or between 30 and 60 mm, or at least 50 mm, or approximately 50 mm. 
     As shown in  FIGS. 6A and 6B , the reinforcement beam  14  is formed with a metal sheet, such as with a stamping, press bending, or roll forming process. The metal sheet includes a martensitic steel with a tensile strength of at least 980 MPa, and in some examples at least 1,500 MPa, such as 1,500 MPa or 1,700 MPa. The metal sheet is formed into a beam shape having at least one tubular section extending along a length of the reinforcement beam  14 . The reinforcement beam  14  may also be formed to have at least two tubular sections that enclose hollow areas that extend continuously along the reinforcement beam. The metal sheet of the reinforcement beam has a thickness of about 1.4 mm, and in some examples may be approximately between 1 mm and 1.8 mm or more generally between 0.8 mm to 3.0 mm. In additional bumper assembles, the reinforcement beam may have different shapes and orientations from that illustrated and may include alternative dimensions and proportions, such as for use with different types of vehicles. 
     Referring again to  FIGS. 5-7 , the reinforcement beam  14  includes two tubular sections  50 ,  52  that extend in parallel and are separated from each other along the length of the beam. As shown in greater detail in  FIG. 6B , the reinforcement beam  14  has upper and lower tubular sections  50 ,  52  that are spaced apart from each other by a portion of the front wall  54  of the reinforcement beam  14 . The upper and lower tubular sections  50 ,  52  of the reinforcement beam  14  have rear walls  56  that are substantially vertically aligned with each other. Further, a top shear wall  58  of the upper tubular section  50  of the reinforcement beam  14  is in planar alignment with a bottom shear wall  60  of a lower tubular section  52  of the reinforcement beam  14 . In additional examples, the beam may have different geometries, such as the two tubular sections sharing a common center wall along the length of the beam. 
     Also, the reinforcement beam may include stiffening features, such as to increase the longitudinal stiffness of the beam along its length. As shown in  FIG. 6B , a stiffening channel  62  is formed in the front wall  54  of each of the tubular sections  50 ,  52  of the reinforcement beam  14 . The stiffening channels  62  protrude into an interior volume of each tubular section  50 ,  52  and function to stiffen the forward-facing or impact surface of the front wall  54  of the reinforcement beam  14 . The stiffening channels  62  shown in  FIG. 6B  include a bend radius of about 6.4 mm. In other examples, the reinforcement beam may be similarly formed with more or fewer stiffening ribs and with different bend radii. 
     As further shown in  FIGS. 5-7 , the crush cans  16  of the bumper assembly  10  may also be embodied in various configurations and materials, such as steel, aluminum, and fiber-reinforced composites, among other materials or combinations thereof. For example, as shown in  FIG. 6A , the crush can  16  has a tubular can portion  64  that is attached between a frame engaging plate  66  and a front plate  68 , such as via welding or other attachment means. The can portion  64  of the crush can  16  provides the side wall of the crush can, which may have a cross-section with a rounded rectangular tube shape. The central axis defined by the tubular shape of the can portion  64  may be angled slightly outward from the frame to the connection with the reinforcement beam  14 , such as shown in  FIG. 8 . The frame engaging plate  66  of the crush can  16  has an opening that can be used for an assembly access opening or for routing a wire harnesses or the like. The peripheral portion of the frame engaging plate  66  defines a frame-side flange that is disposed at and circumscribes a rear end of the crush can  16 . The frame side flange is configured to mount to a frame member F ( FIG. 1 ), such as via fasteners that engage mounting apertures that extend through the peripheral portion of the frame engaging plate  66 . It is contemplated that other fastening techniques may be used to mount the crush cans  16  to the reinforcement beam  14  and the frame member F, such as welding, adhesives, rivets, or other attachments or combinations thereof. 
     As shown in  FIG. 7 , the front plates  68  are attached to the reinforcement beam  14  and may each be considered a connection feature of the reinforcement beam  14 , and in some examples may be integrated with the beam, or in other examples may be considered a portion of the crush can. In other examples, the connection features that hold the crush cans to the reinforcement beam may be various other features, such as fasteners, fastener receivers (e.g., blind rivets or spac nuts), welds, or weld alignment apertures. 
     Referring now to  FIGS. 11-15 , an additional example of a bumper assembly  110  includes a reinforcement beam  114  that has discrete bends at outboard sections of the reinforcement beam  114  for the ends of the reinforcement beam  114  to extend rearward and outward beyond the connections with the crush cans  116  to the outboard portions of the bumper assembly  110  that assist with dispersing impact energy during frontal impact collisions that overlap or otherwise contact the outer or corner sections of the front end of the vehicle. The reinforcement beam  114  has end sections  140 ,  142  that terminate at distal ends  144 ,  146  that are an extended length outboard along the length of the reinforcement beam  114  from the connection between the beam  114  and the crush cans  116 . As shown in the example of  FIGS. 11-15 , the distal ends  144 ,  146  are disposed at an extended length  148  from the connection with the crush cans  116  of approximately 300 mm longitudinally along the center axis of the reinforcement beam  114 . As such, the extended length may also be at least 100 mm, at least 250 mm, between 300 and 500 mm, and/or between 250 and 450 mm. As further shown in  FIGS. 14 and 14A , the distal ends  144 ,  146  of the reinforcement beam  114  extend longitudinally rearward relative to the longitudinal extent of the vehicle frame at least a distance rearward the crush cans  116 . Specifically, the distal ends  144 ,  146  are shown in  FIG. 14A  extending rearward the frame engaging plate  166  of the crush cans  116  a distance  149  of approximately 30 mm. To provide the extended length of the reinforcement beam  114  rearward and outboard, the bend sections  136 ,  138  each have a bend radius of 500 mm. 
     Referring again to  FIGS. 11-12B , the reinforcement beam  114  includes two tubular sections  150 ,  152  formed with a metal sheet with a tensile strength of at least 1,500 MPa that extend in parallel and are separated from each other along the beam. As shown in greater detail in  FIG. 12B , the reinforcement beam  114  has upper and lower tubular sections  150 ,  152  that are spaced apart from each other by a portion of the front wall  154  of the reinforcement beam  114 . The upper and lower tubular sections  150 ,  152  of the reinforcement beam  114  have rear walls  156  that are substantially vertically aligned with each other. The reinforcement beam  114  of  FIGS. 11-15  includes the upper tubular section  150  cut away at the outboard sections of the reinforcement beam  114 , from outboard the crush cans  116  to the distal ends  144 ,  146 . Features of the bumper assembly  110  and associated reinforcement beam  114  and crush cans  116  shown in  FIGS. 11-15  that are similar to the bumper assembly  10  and associated reinforcement beam  14  and crush cans  16  are not described in detail again, and similar reference numbers are used, incremented by 100. 
     Referring now to  FIGS. 16-18 , a further example of a bumper assembly  210  includes a reinforcement beam  214  that also has discrete bends at outboard sections of the reinforcement beam  214  for the ends of the reinforcement beam  214  to extend rearward and outward beyond the connections with the crush cans (not shown). The reinforcement beam  214  includes two tubular sections  250 ,  252  formed with a metal sheet with a tensile strength of at least 1,500 MPa that extend in parallel and are separated from each other along the beam. As shown in  FIG. 17A , the reinforcement beam  214  has upper and lower tubular sections  250 ,  252  that are spaced apart from each other by a portion of the front wall  254  of the reinforcement beam  214 . The upper and lower tubular sections  250 ,  252  of the reinforcement beam  214  have rear walls  256  that are substantially vertically aligned with each other. The reinforcement beam  214 , such as shown in  FIG. 17A , has the lower tubular section  252  with a lower hollow extension to extending the beam downward and forma a relatively larger hollow area at the lower tubular section  252  than the upper tubular section  250 . Features of the bumper assembly  210  and associated reinforcement beam  214  shown in  FIGS. 16-18  that are similar to the bumper assembly  10  and associated reinforcement beam  14  and crush cans  16  are not described in detail again, and similar reference numbers are used, incremented by 200. 
     As shown in  FIG. 19 , the 3D bend unit  70  receives a straight roll formed stick or beam in a direction of material flow. The roll formed stick or beam is then bent by the 3D bend unit  70  to a resulting longitudinal shape of a reinforcement beam. As identified in  FIG. 19 , the end sections of the beam coming out of the 3D bend unit  70  are straight sections, as the 3D bend unit  70  has tolerances as to when it can begin to impart a bend radius on an inserted beam and similarly has tolerances as to when it must terminate a bend radius prior to the beam exiting the bend unit. Accordingly, because the reinforcement beam  314  shown in  FIG. 20  has a longitudinal shape with a longitudinal curvature at its distal ends  344 ,  346 , the straight end sections  340 ,  342  of the formed beam are cut off of the beam as scrap pieces. To avoid the resulting scrap, the reinforcement beam may be redesigned to terminate at the distal ends  444 ,  446  with straight end sections  440 ,  442 , such as shown in  FIG. 21 . While the resulting shape of the reinforcement beam  414  in  FIG. 21  is slightly different from that shown in  FIG. 20 , the overall longitudinal profiles are similar when overlapping, as shown in  FIG. 22 , such as to provide similar impact performance. 
     With further reference to the reinforcement beam  414  of  FIGS. 21 and 23 , the end sections  440 ,  442 , of the reinforcement beam  414  include straight sections that extend to the distal ends  444 ,  446  with a length of 200 mm (at the end entering the bender) and 290 mm (at the end exiting the bender). Also, the central section  434  of the beam  414  is generally straight. The bend sections  436 ,  438  of the beam  414  have a bend radius of 500 mm and have transition sections  436   a ,  436   b ,  438   a ,  438   b  at ends of the bend sections  436 ,  438  that interface with the central section  434  and end sections  440 ,  442  of the reinforcement beam  414 . In the bend unit, going from a straight section to a bend section require 50 mm and going from a bend section to a straight section requires 30 mm. For design symmetry, the transition sections  436   a ,  436   b ,  438   a ,  438   b  each have a length of 50 mm in the reinforcement beam  414  shown in  FIG. 23 . 
     Similarly, the reinforcement beam  514  of  FIG. 24  has end sections  540 ,  542 , that include straight sections that extend to the distal ends  544 ,  546  with a length of 200 mm (at the end entering the bender) and 290 mm (at the end exiting the bender). Also, the central section  534  of the beam  514  has a slight curvature of a 2,800 mm bend radius. The bend sections  536 ,  538  of the beam  514  have transition sections  536   a ,  536   b ,  538   a ,  538   b  at ends of the bend sections  536 ,  538  that interface with the central section  534  and end sections  540 ,  542  of the reinforcement beam  514 . In the bend unit, going from a straight section to a bend section requires 50 mm and going from a bend section to a straight (or slightly curved) section requires 30 mm. Again, however, for design symmetry, the transition sections  536   a ,  536   b ,  538   a ,  538   b  each have a length of 50 mm in the reinforcement beam  514  shown in  FIG. 24 . 
     Features of the reinforcement beams  414  and  514  shown in  FIGS. 20-24  that are similar to the reinforcement beam  14  are not described in detail again, and similar reference numbers are used, incremented by 400 and 500, respectively. 
     Also for purposes of this disclosure, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” “inboard,” “outboard” and derivatives thereof shall relate to the orientation shown in  FIG. 1 . However, it is to be understood that various alternative orientations may be provided, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in this specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     Changes and modifications in the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law. The disclosure has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described.