Abstract:
A bumper system includes a tubular beam having front and rear walls, and a plurality of horizontally-extending walls that interconnect the front and rear walls. An energy absorber has a rear surface with a recess shaped to mateably receive and support the beam, and includes end sections that extend to be coplanar with the rear wall of the beam. The end sections cover the front wall and also at least partially cover a top, bottom and ends of the beam, and are constructed to flex and absorb energy to reduce a likelihood of vehicle damage. In one form, the end sections include honeycomb sections that engage beam mounts to transfer impact energy directly to the mounts. In another form, the end sections include cantilevered flanges that extend outwardly from ends of the energy absorber for impact absorption at the vehicle corners.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of co-assigned, co-pending application Ser. No. 10/061,670, filed Feb. 1, 2002, entitled BUMPER SYSTEM WITH FACE-MOUNTED ENERGY ABSORBER, which in turn claims benefit under 35 U.S.C. 119(e) of a provisional application Serial No. 60/283,969, filed Apr. 16, 2001, entitled BUMPER SYSTEM WITH FACE-MOUNTED ENERGY ABSORBER. 
     
    
     
       BACKGROUND OF THE PRESENT INVENTION  
         [0002]    The present invention relates to automotive bumper systems having beams and energy absorbers located on faces of the beams.  
           [0003]    Many vehicle designs use energy absorbers positioned on a face or front surface of a steel bumper beam to improve energy absorption of a bumper system. The energy absorbers provide an initial level of energy absorption for low impact, including reducing damage during low impact, and also provide a supplemental level of energy absorption during high impact (i.e. before and at the time that the beam and vehicle begin to absorb substantial amounts of energy). Usually, the energy absorbers are fastened to the bumper beam with fasteners that assure accurate positioning of the energy absorber on the beam. The reasoning includes accurately positioning the energy absorber on the bumper beam to assure consistent performance, as well as to assure accurate positioning for aesthetics and assembly (e.g. to assure a good fit of the front-end fascia over the energy absorber and beam during assembly).  
           [0004]    However, improvements are desired in terms of temporary and permanent attachment, and for improved and more reliable energy absorption. Typically, attachment of the energy absorber to bumper beams requires a plurality of mechanical fasteners. This is disadvantageous since mechanical fasteners require manual labor to install, which can add undesirably to cost. Also, the mechanical fasteners can result in localized and non-uniform stress distribution during impact, resulting in inconsistent collapse of the bumper system and poor energy absorption on impact. Further, fixing the energy absorber to the beams results in an inability of the energy absorber to shift and adjust to non-perpendicular and uneven loads transmitted from the impacting bodies. At the same time, depending on the bumper system, sometimes shifting of an energy absorber is not good since it can result in unpredictable, premature and non-uniform collapse, resulting in poor or inconsistent energy absorption by the bumper system.  
           [0005]    Improvement is also desired for corner impact structure on bumper systems. Many existing bumper systems require that a front surface of an end of a bumper beam be shaped at an increased angle relative to the front of rest of the bumper beam to match an aerodynamic curvature of the vehicle at its front fender. One way to achieve this is by miter cutting an end of the bumper beam at an angle, and thereafter welding a plate onto the angled end to form a compound-angled flat front surface for supporting an energy absorber such as a foam cushion. Another way is to deform or crush an end of the bumper beam to form an angled front surface. Yet another way is to weld a bracket onto an end of the bumper beam, with the bracket extending longitudinally beyond the bumper beam to form the desired shape. However, all of these alternatives have drawbacks. For example, they each require a secondary operation, result in increased dimensional variation, and require significant investment in capital equipment. Further, they can lead to increased scrap, a substantial increase in manpower and manufacturing time, and substantial increase in inventories and work in process.  
           [0006]    For all of the above reasons, there is a desire for bumper systems that yield a better, more consistent, more reliable, and greater impact energy absorption, both for low and high impact events, and also for square and skewed impact directions. Also, there is a desire for improvements facilitating assembly of an energy absorber to a beam, with lower cost and fewer parts, and with less labor. Still further, there is a desire for energy absorber designs that allows adjustment and tuning for optimal front end and corner impact strengths, even late in the bumper development program, and yet that do not require expensive or complex molding techniques or assembly techniques nor secondary miter cutting or crush forming bumper end sections. Still further, there is a desire for energy absorber designs that are adaptable for use with many different bumper beam cross-sectional shapes and sizes. Also, energy absorber designs are desired that are flexible and usable on non-linear bumper beams having different curvatures and longitudinal sweeps, and having different cross sections.  
         SUMMARY OF THE PRESENT INVENTION  
         [0007]    In one aspect of the present invention, a bumper system for a passenger vehicle includes a tubular beam having a front wall, at least one rear wall, and a plurality of horizontally-extending walls that interconnect the front and rear walls, the beam being adapted for attachment to a vehicle frame. An energy absorber is provided having a rear surface with a recess shaped to mateably receive and support the beam. The energy absorber includes end sections that extend to a location approximately coplanar with the rear wall of the beam. The end sections of the energy absorber define corners of the vehicle and are configured to structurally support fascia of the vehicle at the corners. The end sections cover the front wall and also at least partially cover top, bottom and ends of the beam, with the end sections being constructed to flex and absorb energy to reduce a likelihood of vehicle damage.  
           [0008]    In another aspect of the present invention, a bumper system for vehicles includes a tubular bumper beam including a front face and opposing ends, and further includes spacedapart mounts supporting the beam and adapted for attachment to a vehicle frame. An energy absorber includes a main section engaging the front face and includes end sections connected to the main section that wrap around the ends and cover the ends and that extend to the mounts. The corner sections each includes perimeter walls defining a tubular section that extends to an associated one of the mounts in a direction generally perpendicular to a length of the tubular bumper beam. The tubular sections are constructed to optimally absorb energy upon corner impact against the bumper system and to communicate a portion of any impact energy directly to the mounts.  
           [0009]    In yet another aspect of the present invention, a bumper system for vehicles includes a bumper beam having a face defining a forward direction for a vehicle and having open ends positioned close to front corners of a vehicle. An energy absorber engages the face and includes a front wall extending generally parallel the face. The energy absorber, when in a vehicle-mounted position, is symmetrically shaped about a transverse vertical central plane, and has a center section engaging the face and covering the face, and further has corner sections covering the open ends of the bumper beam. The corner sections are formed in part by perpendicularly extending walls that form an open honeycomb shaped structure and are formed in part by a cantilevered flange supported in cantilever that extends outwardly from the honeycomb shaped structure in a direction generally parallel a front wall of the energy absorber.  
           [0010]    These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of a bumper system of the present invention, including a bumper tubular beam and an energy absorber on a face of the bumper beam;  
         [0012]    [0012]FIG. 2 is a rear perspective view of the energy absorber of FIG. 1;  
         [0013]    [0013]FIG. 3 is an enlargement of the circled area III in FIG. 1;  
         [0014]    FIGS.  4 - 6  are cross-sectional views of the bumper system of FIG. 1, FIG. 4 being before impact, FIG. 4A being similar to FIG. 4 but showing the structure needed to avoid die lock during molding, FIG. 5 being at a time of low impact, and FIG. 6 being at a time of high impact, respectively;  
         [0015]    FIGS.  7 - 7 B are fragmentary top views of a prior art bumper system, FIG. 7 showing a bumper beam including an angled miter cut (in dashed lines), FIG. 7A showing a plate welded onto the angled end of the bumper beam, and FIG. 7B showing a foam energy absorber on the bumper beam;  
         [0016]    [0016]FIG. 8 is a perspective view of another bumper system including a bumper beam and an energy absorber with rearward projections extending through holes in a front surface of the bumper beam;  
         [0017]    [0017]FIG. 9 is a cross sectional view taken along line IX-IX in FIG. 8;  
         [0018]    [0018]FIG. 10 is a front perspective view of a bumper system including the bumper beam and the energy absorber;  
         [0019]    [0019]FIG. 11 is a rear perspective view of the energy absorber of FIG. 10; and  
         [0020]    FIGS.  12 - 14  are front, top and bottom views of the energy absorber of FIG. 11, and FIG. 15 is an enlarged view of the right half of FIG. 12;  
         [0021]    [0021]FIG. 12A is a front view like FIG. 12, but with a front face of the energy absorber shaded to better show the “box-shaped” areas on the energy absorber;  
         [0022]    FIGS.  16 - 20 ,  22 ,  24 , and  25  are cross sections along the lines XVI-XVI through XXXX, XXII-XXII, XXIV-XXIV, and XXV-XXV in FIG. 15; and  
         [0023]    [0023]FIGS. 21 and 23 are views similar to FIGS. 20 and 22, but after being deformed after impact. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0024]    The present invention is described as utilizing a B-shaped double-tube bumper beam that is rollformed and swept. The present B-shaped bumper beam is sufficiently described herein for a person skilled in the art to understand and practice the present invention, but it is noted that the process and method of making the illustrated B-shaped bumper beam is described in greater detail in Sturrus patent U.S. Pat. No. 5,454,504, if the reader desires such information. It is specifically contemplated that the present invention could be used in combination with a bumper beam having a shallower channel instead of the deep channel illustrated. For example, it is contemplated that the present invention could be made to work on a D-shaped bumper where the bumper beam had a channel extending significantly into a front face of the bumper beam but where the channel does not extend completely to a rear wall of the bumper beam. On the merits, the teachings of U.S. Pat. No. 5,454,504 are incorporated herein in its entirety for the purpose of providing a complete disclosure of the entire bumper system.  
         [0025]    Bumper system  20  (FIG. 1) includes a bumper beam  21  attached to a vehicle, and an energy absorber  22  attached to a face of the bumper beam  21 . The illustrated bumper beam  21  is attached by brackets  20 A. Crush towers can also be used to mount the bumper beam. The illustrated beam is rollformed and swept (see Sturrus patent U.S. Pat. No. 5,454,504) and has a continuous B-shaped double-tubular cross section (FIG. 3). The double tubes are spaced vertically apart and include top and bottom mid-walls  23  and  24  defining a longitudinally-extending channel  25  along its front surface. A polymeric energy absorber  22  has a length with multiple top and bottom box-shaped sections  27  and  27  (not all being the same size or length) that abut the front surface  26  of the bumper beam  21 . The energy absorber  22  further includes a plurality of rearwardly-extending nose sections  28  that extend into the channel  25 . The nose sections  28  are trapezoidally-shaped to fit mateably into the channel  25 , and extend about 50% to 60% of the way to a bottom of the channel  25 . Where desired, the nose sections  28  include detents or are shaped to provide sufficient frictional engagement to temporarily retain the energy absorber  22  on the bumper beam  21 . The illustrated nose sections  28  include collapse-controlling kick walls  30  and  31  that lie along and abut the top and bottom mid-walls  23  and  24  of the bumper beam  21 . The kick walls  30  and  31  are non-parallel and are connected to the box-shaped sections  27  and  27 ′ so that, upon impact by an object against the bumper system, the kick walls  30  and  31  bend in a predictable and preplanned manner and press into the top and bottom mid-walls  23  and  24 . During high impact (see FIGS. 3 and 4), the kick walls  30  and  31  press with increasing force, resulting in a more consistent and controlled flexure and collapse of the box-shaped sections  27  of the polymeric energy absorber  22  and of the tube sections of the metal bumper beam  21  as a system. The nose sections  28  are trapped within the channel  25 , which eliminates the problem of the energy absorber sliding vertically off a face of the bumper beam (which is a problem in some bumper systems using an energy absorber mounted to a face of a bumper beam).  
         [0026]    The B-shaped section of the bumper beam  21  includes, in addition to top and bottom mid-walls  23  and  24 , a top wall  34 , a front upper wall  35 , a bottom wall  36 , a front lower wall  37 , a rearmost rear wall  38  and a channel-forming rear wall  39 . The top tube of the bumper beam  21  is formed by the walls  23 ,  34 ,  35 , and  38 . The bottom tube of the bumper beam  21  is formed by the walls  24 ,  36 ,  37 , and  38 . The top and bottom tubes are interconnected by rear walls  38  and  39 . Each of these walls  23 - 24  and  34 - 39  can be flat or non-flat. For example, in some bumper systems (such as the illustrated walls  23 - 24 ), it has been found to be beneficial to make the horizontal walls  23 ,  24 ,  34 , and  36  slightly bent or curved, both for purposes of providing a bumper beam that is less likely to prematurely kink and more likely to reliably and consistently bend, but also for the purpose of ease of manufacture of the bumper beam. As illustrated, the mid-walls  23  and  24  include front portions that are angled to created a tapered throat into which the nose sections  28  of the energy absorber  22  tend to move upon impact. The mid-walls  23  and  24  also include relatively flat rear portions that are generally parallel. It is noted that, upon a low force impact, the energy absorber  22  may move partially into this throat (see FIGS.  4 - 6 ) and, if sufficient energy is absorbed during the low energy impact, may return to an original shape without substantial deformation or damage to the vehicle or the bumper system.  
         [0027]    The energy absorber  22  (FIG. 3) is a molded component of non-foam polymer, such as a blend of PC/ABS/PBT. For example, it is contemplated that General Electric&#39;s XENOY polymer will work for this purpose. As noted above, the energy absorber  22  includes top and bottom box-shaped sections  27  and  27 ′ that abut a front of the front walls  35  and  37 . The top box-shaped sections  27  engaging the top front wall  35  can be shaped slightly different than the bottom box-shaped sections  27 ′ that engage the bottom front wall  37 , if desired, but in the presently disclosed preferred embodiment, they are similar in size and shape to better assure a uniform and balanced collapse upon impact. The top box-shaped sections  27  include a front wall  41 , open rear area  42 , top wall  43  and bottom wall  44 , as well as end walls  45  and  46  that tie the walls  41 ,  43 - 44  together. The bottom box-shaped sections  27 ′ include similar walls  41 ′- 46 ′. Walls  46 A,  46 B, and  46 C extend between and interconnect the top and bottom box-shaped sections  27  and  27 ′. It is noted that the top and bottom walls  43 ,  44 ,  43 ′, and  44 ′, when viewed from a position in front of the bumper system, can be wavy or otherwise nonlinear and non-flat in shape. This provides the top and bottom walls  43 ,  44 ,  43 ′, and  44 ′ with increased strength for resisting buckling, and also helps eliminate distortions such as snaking that occur when molding a long part. It is also noted that the surfaces defined by the front walls and rear areas  41 ,  42 ,  41 ′, and  42 ′ (and potentially the top and bottom walls  43 ,  44 ,  43 ′ and  44 ′) are discontinuous and further include apertures to prevent die lock when molding. (i.e. They include apertures to allow mold tooling to pass through the plane of one wall to form another wall.) In a preferred form, the apertures are sufficient in size so that the molding dies do not require slides or pulls. In other words, the energy absorber  22  can be made by using hard male and female molds, neither of which require secondary movable die components for creating blind surfaces.  
         [0028]    The nose sections  28  (FIG. 4) include kick walls  30  and  31 , and further include a connector wall  48  that interconnects the leading (rear-most) ends of the kick walls  30  and  31 . The connector wall  48  is located halfway into channel  25  so that it acts as a guide during impact to guide the leading ends of the kick walls  30  and  31  into the channel  25 . Specifically, the connector wall  48  is positioned about 30% to 80% of the way into the channel  25 , or more particularly about 50% to 60% into the channel  25 . This results in the energy absorber  22  being able to absorb significant energy, such as may be incurred in a low energy impact. Specifically, in a low energy impact (FIG. 4), the energy absorber  22  absorbs a majority of the energy of the impact energy, and the energy absorber  22  and the bumper beam  21  do not permanently deform. In an intermediate energy impact (FIG. 5), the energy absorber  22  deforms substantially, potentially taking on a permanent deformation. However, the bumper beam  21  deflects and absorbs energy, but the mid-walls  23  and  24  only temporarily flex and do not permanently deform. In a high-energy impact (see FIG. 6), the kick walls  30  and  31  cause the mid-walls  23  and  24  to buckle as they approach a maximum amount of deflection. Both the energy absorber  22  and the bumper beam  21  permanently deform. The point of buckling is designed into the bumper system  20  to cause a two-step collapse (FIGS.  5 - 6 ) so that a maximum amount of energy is absorbed without damaging the vehicle, while considering all relevant factors such as preferred de-accelerations, occupant safety, government standards, and the like.  
         [0029]    The top kick wall  30  (FIG. 4)includes a root region  50  that connects to the bottom wall  44  of the top box section  27 , and the bottom kick wall  31  includes a root region  51  that connects to the top wall  43 ′ of the bottom box section  27 ′. This direct connection allows the nose section  28  to react quickly and directly to an impact, because the impact energy is transferred directly through the bottom wall  44  of the box section  27  to the kick wall  30 , and because the impact energy is transferred directly through the top wall  43  of the bottom box section  27 ′ to the kick wall  31 . Due to walls  42 , the natural flow of material at  50  and  51  during impact cause the material to move into walls  30  and  31  along directions A and B, respectively (see FIG. 5).  
         [0030]    A top flange  53  (FIG. 4) extends rearwardly from the top box section  27 , and a bottom flange  54  extends rearwardly from the bottom box section  27 ′. The flanges  53  and  54  engage top and bottom surfaces on the bumper beam  21 . Optionally, the flanges  53  and  54  can include attachment tabs or hooks for engaging apertures or features in the bumper beam  21  for retaining (temporarily or permanently) to the bumper beam  21 . The illustrated flanges  53  and  54  include fingertip-like pads  53 ′ and  54 ′ that frictionally engage top and bottom surfaces of the bumper beam  21 . These frictional flanges  53  and  54  are advantageous in that all (or most) fasteners can be eliminated. It is also noted that hooks may extend through holes in the faces  35  and  37  of the bumper beam  21  and retain the energy absorber  22  on the beam  21 .  
         [0031]    It is noted that the present arrangement (see FIGS. 3 and 4- 6 ) “reverses” the B-shaped cross section of the bumper beam  21  relative to the vehicle that it is attached to, which creates a usable energy absorbing crush space within the channel of the bumper beam  21 . Previously, B-shaped bumper beams were typically used with the flat side of the B shape facing forwardly and supporting the energy absorber. However, with the flat side of the B shape facing forwardly, the known energy absorbers can only collapse against the flat side. Thus, energy absorption is more limited than in the present design. Specifically, the present arrangement of FIGS.  4 - 6  provides for a more controlled and predictable two-stage energy absorption upon impact, because the energy absorber kick walls  30  and  31  stabilize the walls  23  and  24  of the bumper beam  21  during initial impact. Further, the arrangement causes the nose section  28  to slide into the channel of the bumper beam  21 , providing an intermediate step of energy absorption, which helps in reading sensor outputs for sensing impacts, such as are used for air bag deployment. Still further, it is believed to be novel to utilize wall structure in an energy absorber to “kick” out and cause predictable collapse of a steel bumper beam (see FIG. 6), as in the present invention described above.  
         [0032]    It is contemplated that corner sections can be molded onto ends of the energy absorber  22  or integrally formed as part of the energy absorber. Advantageously, the corner sections can be specifically designed to satisfy a variety of functional and aesthetic conditions. For example, the corner sections can be square-shaped and can be molded with any amount of wall thickness and ribs desired, such that substantially increased amount of corner impact loading can be successfully dissipated by the corner section. Alternatively, a different polymeric material can be molded onto ends of the energy absorber to create the corner section, such as a glass reinforced stiffer polymeric material.  
         [0033]    FIGS.  8 - 9  show a bumper system  200  including a D-shaped single-tube bumper beam  201  supported on mounting towers  202 , and an energy absorber  203  that functions similar to the bumper beam  20  and energy absorber  21  discussed above. The bumper beam  201  includes two spaced apertures  204  in its front surface  205 , and the energy absorber  203  includes rearwardly projecting nose sections  206  that project through the apertures  204  and that extend to the rear wall  207  of the bumper beam  201 . The illustrated nose sections  206  abut the rear wall  207 , but it is noted that they can terminate short of the rear wall  207  to provide a stepped crush stroke that provides different levels of energy absorption at different impact stroke depths. It is contemplated that more or less apertures  204  and nose sections  206  can be used. During a vehicle impact, the nose sections  206  provide an initial level of impact strength and energy absorption. As the impact stroke increases, the nose sections  206  buckle outwardly, and engage top and bottom walls of the bumper beam  201 . An advantage of the bumper system  200  is that it provides good localized control and a consistent and repeatable energy absorption over energy absorption during impact.  
         [0034]    Prior art (FIGS.  7 - 7 B) includes a B-shaped bumper beam  221 , miter cut at an angle along a line  222 , with a flat plate  223  welded onto the cut end to provide an extended flat front surface having an increased angle at the miter cut end. A foam energy absorber  224  is positioned against the flat front surface of the bumper beam  221 , and extends onto the flat plate  223 . The arrangement below eliminates the need to miter cut ends of a bumper beam, which is advantageous because miter cutting is an expensive secondary operation that takes time, money, equipment, and results in increased inventories. The invention described below eliminates the miter cutting and secondary operations needed in the bumper system  221 / 222 .  
       Modification  
       [0035]    Bumper system  100  (FIG. 10) includes a B-shaped bumper beam  101  and an energy absorber  102  attached to the beam&#39;s “flat” front face. The energy absorber  102  incorporates box-shaped sections similar to the concept of the energy absorber  22  previously described, but does so in a manner permitting the energy absorber  102  to be used on the “flat” side of the B-shaped bumper beam  101  (i.e. the side of the B-shaped bumper beam  101  that does not have a channel formed in it (see FIGS. 18 and 20)), as described below. Also, the energy absorber  102  can be used on a D-shaped or single tube bumper beam.  
         [0036]    The bumper beam  101  has the same shape and walls as the bumper beam  21 , except that the bumper beam  101  has an opposite longitudinal curvature for matching an aerodynamically-shaped curved front of a vehicle. In the beam  101 , the longitudinal curvature places the “flat” surface  103  (FIG. 20) on a fiont side of the bumper beam  101 , and the two tube sections  104  and  105  and the channel  106  therebetween on a rear side of the beam  101 . Two mounting brackets or plates  107  and  108  (FIG. 10) are attached to the tube sections  104  and  105 . The mounting plates  107  and  108  each have a flat plate section  109  that engages and is welded to a back side of the tube sections  104  and  105 . A section  110  (FIG. 13) extends from the mounting plates  107  and  108  at a location about 1 inch to 1½ inches from an end of the tube sections  104  and  105 . The sections  110  each include an outer leg  112  that extends rearward of the plate section  109 , generally at a corner of the vehicle. It is contemplated that the mounting plates  107  and  108  can have a forward loop  111  that partially covers an end surface of the energy absorber if desired (see FIG. 25). Coplanar flanges  113  and  114  (FIG. 13) extend from the rear/outer ends of the brackets  107  and  108 . It is noted that other mounting systems can be used for vehicle attachment on the present bumper system if desired.  
         [0037]    The energy absorber  102  is symmetrical about a centerline  115  (FIG. 12A), with each half of the energy absorber  102  including four box-shaped sections  117 - 120 , each being interconnected by longitudinally-extending walls, as described below. The box-shaped section  117  (FIG. 12A) is adjacent the centerline  115  and includes a front face wall  121 , a top wall  122 , a bottom wall  123 , an inboard sidewall  124  and an outboard sidewall  125 . A rear of the box-shaped section  117  is open and the walls  122 - 125  have draft angles, so that the box-shaped section  117  can be formed on molding dies that do not require die pulls or other moving parts for forming blind surfaces. Two large “crush-initiator” apertures  126  (FIG. 15) are formed in the inboard sidewall  124  to weaken the box-shaped section  117 , to provide for an optimal crush stroke upon impact against the bumper system  100  and specifically to provide for optimal energy absorption during the crush stoke. The illustrated apertures  126  are each about ⅓ of a total height of the inboard sidewall  124  (see FIG. 18), are located at a top third and a bottom third of the sidewall  124 , and extend to a full depth of the sidewall  124 . Different shapes of apertures can be used. The illustrated apertures  126  are not rectangular, but instead have at least one curved edge  126 ′, which is designed to initiate a controlled crush during an impact for optimal energy absorption during impact, and which is also designed to facilitate molding. A strip of material between the apertures  126  and also the strips of material above and below the apertures  126  form the structure of sidewall  124 . Apertures  127  (FIG. 15) are also formed on the front face wall  121  as desired, such as to reduce mass, improve tooling, and provide clearances and attachments to fascia. The outboard sidewall  125  has a C-shaped profile (when viewed in a car-mounted position), and has a vertical center portion  128  that is located closer to the centerline  115  than the upper and lower portions. A top angled portion  129  of the front face wall  121  slopes rearwardly from a remainder of the vertical front face wall  121 , which is more vertically oriented, but not perfectly vertical.  
         [0038]    The box-shaped section  118  (FIG. 12A) is adjacent the box-shaped section  117  and includes a front face wall  131 , a top wall  132 , a bottom wall  133 , an inboard sidewall  134  and an outboard sidewall  135 . The box-shaped section  118  is about double a width of the box-shaped section  117  (in a longitudinal direction), and the inboard sidewall  135  is C-shaped to a longitudinal width about double the dimension of the C-shape of the outboard sidewall  124  of the center box-shaped section  117 . Also, a top angled portion  139  of the front face wall  131  has a vertical dimension that is slightly less than the top angled portion  129  of the center box-shaped section  117 , so that the combined front face of the energy absorber matches a shape of the fascia panel placed on it. The outboard sidewall  135  (FIG. 17) has three apertures  136  that are similar to the apertures  126  found in the sidewall  124  described above, with the exception that one of the apertures  136  is formed in each third of the outboard sidewall  135 .  
         [0039]    The box-shaped section  119  (FIG. 12A) is adjacent the box-shaped section  118  and includes a front face wall  141 , a top wall  142 , a bottom wall  143 , an inboard sidewall  144  and an outboard sidewall  145 . The box-shaped section  119  is about ⅔ of a width of the box-shaped section  118  (in a longitudinal direction). The inboard and outboard sidewalls  144  and  145  are relatively flat (i.e. are not C-shaped). Also, a top angled portion  149  of the front face wall  141  has a vertical dimension that is slightly less than the top angled portion  139  of the box-shaped section  118 , so that the combined front face of the energy absorber matches a shape of the fascia panel placed on it. The inboard and outboard sidewalls  144  and  145  each have two apertures  146  (FIG. 20) that are similar to the apertures  126  found in the sidewall  124  described above, with the exception that the inboard sidewall  144  also has a center aperture  146 .  
         [0040]    The box-shaped section  120  (FIG. 12A) is adjacent the box-shaped section  119  and includes a front face wall  151 , a top wall  152 , a bottom wall  153 , an inboard sidewall  154  and an outboard sidewall  155 . The box-shaped section  120  is about equal in width to the box-shaped section  117  (in a longitudinal direction). The inboard and outboard sidewalls  154  and  155  are relatively flat (i.e. are not C-shaped). Also, the front face wall  151  extends to a top of the box shaped section  120 , and there is not a top angled portion like the other box-shaped sections  117 - 119 . The inboard sidewall  154  has two apertures  156  that are similar to the apertures  126  found in the sidewall  124  described above. The illustrated box-shaped section  120  is actually divided into vertically-spaced-apart halves, and consistent with that the front face wall  151  and also the inboard and outboard sidewalls  154  and  155  are actually divided into top and bottom halves, with the center section being entirely open except for a vertical stabilizing rib  157 .  
         [0041]    The illustrated box-shaped sections  117 - 120  are connected together by interconnecting “honeycomb-shaped” structures in the form of four horizontal ribs  160 - 163  (FIG. 12A) that are spaced equally apart in a vertical direction. It is contemplated that the box-shaped sections  117 - 120  can be connected together by different arrangements and still incorporate many of the advantages of the present energy absorber. The top rib  160  and the bottom rib  163  extend continuously from end to end of the energy absorber  102 . The middle two ribs  161  and  162  also extend end to end of the energy absorber  102 , with the exception that the middle ribs  161  and  162  are discontinued near the centerline  115  and do not connect the two center box-shaped sections  117 . Also, the ribs  161  and  162  connect the top and bottom legs of the C-shaped inner portion of walls  125  and  134 . The box-shaped sections  117 - 120  are also connected together by a rear wall  164 . The rear wall  164  completely covers a rear of the energy absorber  102 , with the exception that an opening is formed in the rear wall  164  at each of the box-shaped sections  117 - 120  to facilitate tooling and prevent a die lock condition. The rear wall  164  not only ties the sections  117 - 120  together, but also forms vertical straps that tie the top and bottom walls together to prevent the top and bottom walls from spreading apart during an impact. This also eliminates the need for top and bottom fasteners.  
         [0042]    A top flange  170  (FIG. 13) and a bottom flange  171  (FIG. 14) are formed on top and bottom edges of the rear wall  164 . The flanges  170  and  171  wrap onto tops and bottoms of the bumper beam  101 . Fingertip-like pads  172  are formed on the flanges  170  and  171  for engaging mating areas on the top surface and on the bottom surface of the bumper beam  101  to temporarily frictionally retain the energy absorber  102  on the bumper beam  101 . Also, hooks  173  (FIGS.  10 - 11 ) are formed on tabs that extend from (and co-planar with) the top and bottom walls  122 ,  123 ,  132 ,  133 ,  142 ,  143 ,  152 , and  153 . The hooks  173  are shaped to engage mating holes in a front face of the bumper beam  101 . The hooks  173  (and also flanges  53 - 54 ) provide an opportunity for “blind” snap-attachment, such as when an operator has preassembled an energy absorber to a fascia, and then attaches the assembled absorber/fascia as a unit to a vehicle front. In such event, the fascia prevents the operator from attaching the absorber to a bumper beam.  
         [0043]    The energy absorber  102  (FIG. 11) includes integrally-formed end sections  180  and  181  that are symmetrically shaped and that are optimally shaped to form end-located crush boxes for energy absorption upon corner impact to a vehicle. The end sections  180  and  181  each include a vertical rib  182  (FIG. 12A) that transversely crosses and connects to the horizontal ribs  160 - 163  to form a honeycomb shape. The outboard sidewall  155  is extended rearwardly so that it substantially covers the open end of the tube sections on the bumper beam  101 . Also, the rear wall  164  is extended at a location  164 ′ (FIGS. 22, 24, and  25 ) from the outboard sidewall  155  to form a rearwardly extending box  164 ″ (FIG. 25) that fits adjacent an end of the bumper beam. It is noted that the mounting brackets  107  and  108  can include a forward loop  111  that holds the box  164 ′ in place against an end of the bumper beam, if desired. A crescent-shaped flange  183  extends coplanar with the face front walls  121 ,  131 ,  141 , and  151 .  
         [0044]    The flange  183  is stiff but flexible, such that it does a good job of supporting front-end fascia, such as RIM urethane fascia, placed on it. At the same time, the flange  183  is flexible for flexing during a corner impact on a vehicle, thus reducing damage to the vehicle.  
         [0045]    The illustrated top and bottom walls  122 ,  123 ,  132 ,  133 ,  142 ,  143 ,  152 , and  153  are wave-shaped or corrugated in shape to facilitate molding and strength. The illustrated walls of the box-shaped sections  117 - 120  and walls  160 - 163  and adjacent areas are about 2 mm thick, while the walls of the end sections  180  and  181  are about 3 to 4 mm thick. (Compare FIGS.  16 - 20  to the FIGS.  22 - 25 .) However, it is contemplated that the walls and thickness can be made any thickness, including localized variations made to optimize the energy absorption. Since the mold dies are relatively non-complex (since pulls and movable components for making blind surfaces are not required), the walls can be made thicker relatively easily by grinding away metal in the molding dies. Also, the apertures can be made smaller by grinding away metal, such that the crush/impact strength can be closely and accurately controlled, and also can be carefully adjusted and tuned to react to the actual results of vehicle crash testing during bumper development for a particular model vehicle. For example, by reviewing the energy absorber  102  and bumper beam  101  after an impact (compare FIGS. 20 and 22 which are before impact, and FIGS. 21 and 23 which are after impact), intelligent decisions can be made regarding what areas of the energy absorber  102  require additional strength, and what areas need to be weakened. For example, by changing a shape of the curved edge of the apertures  126 ,  136 ,  146  and  156 , a different energy absorption curve results on a force vs deflection graph of a vehicle impact. Specifically, the rates of increase in energy absorption can be controlled and more accurately adjusted while “tweaking” and fine-tuning the energy absorber  102 . Substitution of different material blends in the energy absorber  102  also can help.  
         [0046]    In particular, it is noted that the end sections  180  and  181  of the present energy absorber  102  form integral box-shaped sections that provide a very consistent and strong corner impact strength. The honeycomb shape formed by ribs  160 - 163  and ribs  153  and  182  along with the crescent-shaped flange  183  and the interaction of the end sections  180 - 181  with the J-shaped section  110  of the mounting bracket  107  and  108  and the end of the tube sections  104  and  105  of the bumper beam  101  are important aspects of the present invention. Also, an important inventive aspect is the concept of fine-tuning the energy absorber  102  by changing wall thicknesses and providing apertures of different sizes to optimize a bumper system.  
         [0047]    Yet another important feature of the present illustrated design of the energy absorber  102  is shown by the offset  163 A in lower wall  163 , which connects the front and rear portions  163 B and  163 C of wall  163 . During impact, the front portion  163 B telescopes overlappingly onto the rear portion  163 C, with the offset  163 A wrapping back upon itself and between the portions  163 B and  163 C. This “wrapping” action provides high energy absorption and a very consistent and predictable collapse, which is very desirable in energy absorbers.  
         [0048]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. Further, it is to be understood that methods related to the above concepts are believed to be within a scope of the present invention.