Patent Publication Number: US-2007120383-A1

Title: Bumper system

Description:
RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Application 60/730,327, filed Oct. 26, 2005, the entirety of the previously filed application being incorporated herein by reference. 
    
    
     BACKGROUND  
      1. Field of the Invention  
      The present invention relates to the field of modular bumper systems.  
      2. Background  
      Bumpers are an integral part of any vehicle. The primary function of a bumper is to absorb and distribute impact loading during a collision, thus providing an important safety feature of the vehicle. While a bumper can assume a variety of configurations for providing safety, it is often desirable that the shape of the bumper conform to the overall styling of the vehicle. Additionally, reducing the bumper weight is an important consideration (for meeting fuel efficiency standards, for example).  
      Bumpers have traditionally been roll formed or stamped from a single blank of material such as steel, and are rigidly attached to a frame of a vehicle. A roll formed bumper generally takes the shape of an arch, with a front beam or panel of the bumper forming an apex of the arch that faces forward toward the direction of travel. The bumper can then absorb impact loading through deformation, i.e., flattening, of the arch. However, flattening of the bumper under impact loading will tend to push the vehicle frame elements outward, thus causing considerable structural damage.  
      Resistance of the bumper to deformation under impact loading is generally a function of the size, shape, and strength of the material forming the bumper. Since the strength of the bumper is directly related to its size, it is difficult to obtain a bumper of sufficient strength while at the same time minimizing its weight and thus improving the vehicle&#39;s fuel efficiency. U.S. Pat. No. 6,926,320 (assigned to Meridian Automotive Systems, Inc.) provides examples and descriptions of the general background of bumper systems, and the specification of this patent is incorporated herein by reference as though set forth here in full.  
      One bumper system design consideration is impact performance. It is preferable that the front beam or panel of a bumper system meet vehicle manufacturer specifications, such as a barrier impact test (a flat plate impact test) or a pendulum impact test (a weighted device that swings into a vehicle), without damaging adjacent systems.  
      Other bumper system design considerations include noise, vibration, and harshness (“NVH”) considerations. The front beam or panel of a bumper system is the first cross member of the vehicle frame and is an integral component of front-end frame characteristics. The bumper beam design must also accommodate studio design constraints, which can include aesthetic characteristics (such as a highly swept front end and an increased vehicle length, for example).  
      Past attempts to solve these functional and aesthetic design constraints have fallen short. For example, bumper systems have employed a roll formed beam in a B-shaped section, but a roll formed B-shaped beam is difficult to make, cannot be swept (or arched) easily, and has a high weight for its given performance. Bumper systems have also employed a roll formed beam in a box-shaped section, but a roll formed box-shaped beam also cannot be easily swept and has reduced angle barrier performance (more deflection during corner or angle barrier impact tests). Other bumper systems have used a roll formed beam (with any shape cross-section) with stamped end cap portions. Although the stamped end cap portions can provide more strength and a shape that fits under a vehicle fascia, these beams also cannot be easily swept and have a higher cost than other designs. Likewise, extruded bumper beams (such as extruded aluminum bumper beams) also have a higher cost than other designs. Other structures, such as energy management isolators that fit between a bumper beam and a vehicle fascia and that can reduce deflection during an impact, also add weight and cost to the bumper system. Accordingly, a bumper system is desired solving the aforementioned problems.  
     SUMMARY  
      In one embodiment, there is provided a bumper system comprising an outer panel with a length extending from a first end to a second end, the outer panel comprising a substantially uniform cross-section between the first end and the second end; an inner panel with a length extending from a first end to a second end, the inner panel comprising a substantially uniform cross-section between the first end and the second end; and wherein the first end of the outer panel is joined to the first end of the inner panel and the second end of the outer panel is joined to the second end of the inner panel.  
      In another embodiment, there is also provided a bumper system comprising an outer panel extending from a first end to a second end and comprising a substantially uniform cross-section between the first end and the second end; an inner panel extending from a first end to a second end and comprising a substantially uniform cross-section between the first end and the second end; and wherein the outer panel and the inner panel are connected by one or more supports.  
      In another embodiment, there is also provided a method comprising joining a first end of an outer panel to a first end of an inner panel; joining a second end of the outer panel to a second end of the inner panel; and wherein the outer panel comprises a substantially uniform cross-section between the first end and the second end, and wherein the inner panel comprises a substantially uniform cross-section between the first end and the second end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Embodiments of the present invention are described herein with reference to the drawings, in which:  
       FIG. 1  depicts an example embodiment of a bumper system for a vehicle;  
       FIG. 2  depicts an exploded view of the bumper system of  FIG. 1 ;  
       FIG. 3  depicts an alternate configuration of the bumper system;  
       FIG. 4  depicts an alternate configuration of the bumper system;  
       FIG. 5  depicts an alternate configuration of the bumper system;  
       FIG. 6  depicts an alternate configuration of the bumper system;  
       FIG. 7  depicts a support for the bumper system;  
       FIG. 8  depicts a support for the bumper system;  
       FIG. 9  depicts a support for the bumper system;  
       FIG. 10  depicts an example embodiment of a crushable module;  
       FIG. 11  depicts an example embodiment of a crushable module;  
       FIG. 12  depicts alternate configurations of an outer panel;  
       FIG. 13  depicts alternate configurations of the outer panel;  
       FIG. 14  depicts another example of an assembled bumper system;  
       FIG. 15  depicts an exploded view of the bumper system of  FIG. 14 ;  
       FIGS. 16A-16D  depict several different views of the inner panel of  FIG. 15 ;  
       FIGS. 17A-17E  depict several different views of the outer panel of  FIG. 15 ;  
       FIGS. 18A-18E  depict several different views of the support of  FIG. 15 ;  
       FIG. 19  depicts a cross-section through the bumper system of  FIG. 14 ;  
       FIG. 20  depicts an example crushable module;  
       FIGS. 21A-21D  depict several different views of the crushable module of  FIG. 20 ;  
       FIG. 22  depicts another example of an assembled bumper system;  
       FIG. 23  depicts an exploded view of the bumper system of  FIG. 22 ;  
       FIGS. 24A-24D  depict several different views of the inner panel of  FIG. 23 ;  
       FIGS. 25A-25E  depict several different views of the outer panel of  FIG. 23 ;  
       FIGS. 26A-26E  depict several different views of the support of  FIG. 23 ; and  
       FIG. 27  depicts a cross-section through the bumper system of  FIG. 22 .  
    
    
     DETAILED DESCRIPTION  
      The below-described embodiments allow for bumper system construction using bumper beams with uniform cross-sections. In the manner of the examples described below, two bumper beams, each with a uniform cross-section, can be joined to produce a bumper system with a non-uniform cross-section. Thus, the cross-section of the example bumper systems described herein is narrower toward each end and deeper in the middle. Such a bumper system can function like a bumper system manufactured by a different process or using different components, i.e., a bumper system with bumper beams having deeper or non-uniform cross-sections.  
      In addition, the below-described embodiments can provide several advantages for a bumper system and for a vehicle employing the bumper system. For example, embodiments can provide for a lightweight, truss-type bumper beam, which meets vehicle packaging, strength, and impact requirements. As another example, embodiments can provide for a modular system, allowing different vehicle bumper beams to be manufactured using the same tools. As yet another example, embodiments can provide for a universal bumper beam that can have a common envelope or exterior shape, but that can have different crush modules internally (allowing one to custom tune performance of the bumper system to different vehicle requirements). As still another example, embodiments can provide for a hybrid bumper system that uses steel or aluminum outer panels joined with composite inner modules or supports. Moreover, embodiments can also integrate components in the bumper system to save space, to reduce the number of parts, and to reduce the complexity of assembly; provide high strength to weight ratio; effectively manage the transfer of energy due to impact; protect the surrounding vehicle systems and the vehicle rails; and/or provide high sweep designs that conform to the overall styling of a vehicle.  
     FIRST EXAMPLE EMBODIMENT  
       FIG. 1  depicts an example embodiment of a bumper system  10  for a vehicle. The bumper system  10  can be mounted on the front or the back of a vehicle and can absorb some or all of an impact on that vehicle. The bumper system  10  can thus make a vehicle and its occupants safer and can reduce damage to a vehicle resulting from an impact or an accident.  
       FIG. 2  depicts an exploded view of the bumper system  10  of  FIG. 1 . The example embodiment of  FIGS. 1 and 2  includes an inner panel  1  that mounts to a frame of a vehicle. The inner panel  1  can be a formed open section, such as the W-shaped section depicted in  FIG. 2 , and can have a uniform or variable cross section. The inner panel  1  can be formed of metal or metal alloys by rolling or stamping, although other examples are possible as well.  
      As depicted in  FIGS. 3-6 , the inner panel  1  can comprise various configurations. For example, the inner panel  1  may be bent, as depicted in  FIG. 3 , straight, as depicted in  FIG. 4 , or swept, as depicted in  FIG. 5 . In some embodiments, the inner panel  1  can be a simple C-shaped section, such as depicted in  FIG. 4 , or it might include other or additional features and shapes, such as a W-shaped section, as depicted in  FIG. 6 . Such additional features and shapes can provide additional strength and crush/impact capabilities to the bumper system  10 .  
      Turning back to  FIGS. 1 and 2 , the example bumper system  10  can further include an outer panel  2 , which provides a primary impact surface for the bumper system  10 . The outer panel  2  can be a formed open section, such as the C-shaped section depicted in  FIG. 2 , and can have a uniform or variable cross section. The outer panel  2  can be the same or different gauge as the inner panel  1 , and likewise the outer panel  2  can comprise the same or different cross-sectional shape as the inner panel  1 . The outer panel  2  can be formed of metal or metal alloys by rolling or stamping, although other examples are possible as well.  
      As depicted in  FIG. 12 , the outer panel  2  can comprise various configurations. For example, the outer panel  2  may be swept (in any of a number of different arcs), as depicted in the upper drawing of  FIG. 12 , or bent, as depicted in the lower drawing of  FIG. 12 . In some embodiments, the outer panel  2  can be a simple C-shaped section, such as depicted in  FIG. 2 , or it might include other or additional features and shapes, such as a W-shaped section, for example. Such additional features and shapes can provide additional strength and crush/impact capabilities to the bumper system  10 .  
      Turning back to  FIGS. 1 and 2 , the example bumper system  10  can further include at least one support  3 . The support  3  can provide a structure between the inner panel  1  and the outer panel  2 , and is typically located at the center of the panels, although other locations are possible as well. Although only one support  3  is depicted in  FIGS. 1 and 2 , in other embodiments there may be more than one support  3  to support the two panels. As depicted in  FIGS. 7 and 8 , the support  3  may be a single plate, multiple plates, a simple stamping, roll formed, or an engineered, crushable stamping, although other examples and shapes are possible as well. As depicted in  FIG. 9 , the support  3  may be a simple composite part or an engineered, composite member. A composite support  3  can be made of any composite material or materials, including, for example, injection molding, thermoplastic, or thermoset composite materials.  
      In any case, the inner panel  1  and the outer panel  2  can also be joined at the outer corners (in addition to being joined at the support  3 ) to form one complete assembly. Joining methods between the inner panel  1  and the outer panel  2 , as well as between the inner panel  1 , the outer panel  2 , and the support  3 , may include welding, mechanical fastening, and bonding. If the support  3  is a composite, it may also be joined to one or both of the inner panel  1  and the outer panel  2  with snap features.  
       FIGS. 10 and 11  depict example embodiments of crushable modules  4 . In some embodiments, one or more modules  4  may be installed between the inner panel  1  and the outer panel  2 . The modules  4  can be located at the ends of the inner panel  1  and the outer panel  2 , or at the center of the inner panel  1  and the outer panel  2 , although other locations are possible as well.  
      The modules  4  may be a crushable stamping, as depicted in  FIG. 10 , or an engineered composite part, as depicted in  FIG. 11 . The modules  4  can provide additional energy management capabilities between the inner panel  1  and the outer panel  2  and to the bumper system  10  (such as for flat and angle barrier impact tests, as well as for pole impact tests (where the vehicle backs into a pole at 5 m.p.h., for example)). By including the modules  4 , the gauge of the material of the inner panel  1  and/or the outer panel  2  may be reduced, thereby reducing the weight of the bumper system  10 . The modules  4  can also provide support to the inner panel  1  and/or the outer panel  2 .  
      Joining methods between the inner panel  1 , the outer panel  2 , and the modules  4  can include welding, mechanical fastening, and bonding. If the modules  4  are composite, they may also be joined to one or both of the inner panel  1  and the outer panel  2  with snap features.  
      Various configurations of the inner panel  1  can be combined with various configurations of the outer panel  2 .  FIG. 13  depicts several examples of a straight, swept, and bent inner panel  1  combined with the outer panel  2 . Other examples are possible as well.  
     Second Example Embodiment  
       FIGS. 14-21  depict another example embodiment of the bumper system  10 .  FIG. 14  depicts an assembled bumper system  10 , which can be attached to the front or back of a vehicle and can absorb some or all of an impact on that vehicle.  
       FIG. 15  depicts an exploded view of the bumper system  10  of  FIG. 14 . The example embodiment of  FIGS. 14 and 15  includes an inner panel  1  that mounts to a frame of a vehicle. The inner panel  1  can be a formed open section, such as the C-shaped section depicted in  FIG. 15 , and can have a uniform cross section. The inner panel  1  can be formed of metal or metal alloys by rolling or stamping, although other examples are possible as well. As depicted in  FIG. 15 , the inner panel  1  can comprise a bent configuration, although other configurations, such as the example configurations depicted in  FIGS. 3-6 , are also possible. In one embodiment, the inner panel  1  is a roll formed high strength M220 steel (martensitic) C-shaped section. Other examples are possible as well.  
       FIGS. 16A-16D  depict several different views of the inner panel  1  of  FIG. 15 .  FIG. 16A  depicts an isometric view of the inner panel  1 ;  FIG. 16B  depicts a front view of the inner panel  1 ;  FIG. 16C  depicts a top view of the inner panel  1 ; and  FIG. 16D  depicts a side view of the inner panel  1 .  
      As also depicted in  FIG. 15 , the example bumper system  10  can further include an outer panel  2 , which provides a primary impact surface for the bumper system  10 . The outer panel  2  can be a formed open section, such as the W-shaped section depicted in  FIG. 15 , and can have a uniform cross section. The outer panel  2  can be the same or different gauge as the inner panel  1 , and likewise the outer panel  2  can comprise the same or different cross-sectional shape as the inner panel  1 . The outer panel  2  can be formed of metal or metal alloys by rolling or stamping, although other examples are possible as well. As depicted in  FIG. 15 , the outer panel  2  can comprise a swept configuration, although other configurations, such as the example configurations depicted in  FIG. 12 , are also possible. In one embodiment, the outer panel  2  is a roll formed high strength M220 steel (martensitic) W-shaped section. In one embodiment, the outer panel  2  can be attached to the inner panel  1  by 2×120 mm welds at each end of the tops of the panels and by 2×120 mm welds at each end of the bottoms of the panels. Other examples are possible as well.  
       FIGS. 17A-17E  depict several different views of the outer panel  2  of  FIG. 15 .  FIG. 17A  depicts an isometric view of the outer panel  2 ;  FIG. 17B  depicts a front view of the outer panel  2 ;  FIG. 17C  depicts a top view of the outer panel  2 ;  FIG. 17D  depicts a side view of the outer panel  2 ; and  FIG. 17E  depicts a section through the outer panel  2  showing the W-shape of the example outer panel  2  and some example dimensions.  
      Turning back to  FIGS. 14 and 15 , the example bumper system  10  can further include at least one support  30 . The exploded view of  FIG. 15  depicts the support  30  as an upper support  30 A and a lower support  30 B. The support  30  can provide a structure between the inner panel  1  and the outer panel  2 , and is typically centered on the panels, although other locations are possible as well. Although two supports  30  are depicted in  FIG. 15 , in other embodiments there may be more or less supports  30 . As depicted in  FIGS. 14 and 15 , the support  30  can comprise one or more wave shapes, wherein the tops of the waves can all be attached to one of the panels and the bottoms of the waves can all be attached to the other panel. In one embodiment, the center support  30  comprises a stamped, high strength RA120 steel support. In another embodiment, the center support  30  comprises a stamped, high strength DF140 steel support. Other examples and shapes are possible as well. In addition, in one embodiment, supports  30 A and  30 B can each be attached to the inner panel  1  and the outer panel  2  with 11×30 mm welds at each of the tops and bottoms of the one or more wave shapes.  
       FIGS. 18A-18E  depict several different views of the support  30  of  FIG. 15 .  FIG. 18A  depicts an isometric view of the support  30 ;  FIG. 18B  depicts a front view of the support  30 ;  FIG. 18C  depicts a top view of the support  30 ;  FIG. 18D  depicts a side view of the support  30 ; and  FIG. 18E  depicts a section through the support  30  and shows some example dimensions.  
       FIG. 19  depicts a cross-section through the bumper system  10  of  FIG. 14 , at a point at or near the center of the bumper system  10  along the width of a vehicle. As shown in  FIG. 19 , the outer panel  2  comprises a W-shaped cross-section and the inner panel  1  comprises a C-shaped section.  FIG. 19  also depicts the profiles of a portion of support  30 A and support  30 B.  
       FIG. 20  depicts an example crushable module  40 . In some embodiments, one or more modules  40  may be installed between the inner panel  1  and the outer panel  2 . The modules  40  can be located at the ends of the inner panel  1  and the outer panel  2 , or at the center of the inner panel  1  and the outer panel  2 , although other locations are possible as well. In some embodiments, the crushable modules  40  are stamped from SAE 1010DQ steel. Further, in some embodiments, the crushable modules  40  can be attached to the inner panel  1  with 2×25 mm vertical welds, although other examples are possible as well.  
       FIGS. 21 A-21D  depict several different views of the crushable module  40  of  FIG. 20 .  FIG. 21A  depicts an isometric view of the crushable module  40 ;  FIG. 21B  depicts a front view of the crushable module  40 ;  FIG. 21C  depicts a top view of the crushable module  40  and shows some example dimensions; and  FIG. 21D  depicts a side view of the crushable module  40  and shows an example dimension.  
     Third Example Embodiment  
       FIGS. 22-27  depict another example embodiment of the bumper system  10 .  FIG. 22  depicts an assembled bumper system  10 , which can be attached to the front or back of a vehicle and can absorb some or all of an impact on that vehicle.  
       FIG. 23  depicts an exploded view of the bumper system  10  of  FIG. 22 . The example embodiment of  FIGS. 22 and 23  includes an inner panel  1  that mounts to a frame of a vehicle. The inner panel  1  can be a formed open section, such as the C-shaped section depicted in  FIG. 23 , and can have a uniform cross section. The inner panel  1  can be formed of metal or metal alloys by rolling or stamping, although other examples are possible as well. As depicted in  FIG. 23 , the inner panel  1  can comprise a bent configuration, although other configurations, such as the example configurations depicted in  FIGS. 3-6 , are also possible. In one embodiment, the inner panel  1  is a roll formed high strength M220 steel (martensitic) C-shaped section. In another embodiment, the inner panel  1  is a roll formed high strength SAE 1010 steel C-shaped section. Other examples are possible as well.  
       FIGS. 24A-24D  depict several different views of the inner panel  1  of  FIG. 23 .  FIG. 24A  depicts an isometric view of the inner panel  1 ;  FIG. 24B  depicts a front view of the inner panel  1 ;  FIG. 24C  depicts a top view of the inner panel  1 ; and  FIG. 24D  depicts a side view of the inner panel  1 .  
      As also depicted in  FIG. 23 , the example bumper system  10  can further include an outer panel  2 , which provides a primary impact surface for the bumper system  10 . The outer panel  2  can be a formed open section, such as the W-shaped section depicted in  FIG. 23 , and can have a uniform cross section. The outer panel  2  can be the same or different gauge as the inner panel  1 , and likewise the outer panel  2  can comprise the same or different cross-sectional shape as the inner panel  1 . The outer panel  2  can be formed of metal or metal alloys by rolling or stamping, although other examples are possible as well. As depicted in  FIG. 23 , the outer panel  2  can comprise a swept configuration, although other configurations, such as the example configurations depicted in  FIG. 12 , are also possible. In one embodiment, the outer panel  2  is a roll formed high strength M220 steel (martensitic) W-shaped section. In one embodiment, the outer panel  2  can be attached to the inner panel  1  by 2×120 mm welds at each end of the tops of the panels and by 2×120 mm welds at each end of the bottoms of the panels. Other examples are possible as well.  
       FIGS. 25A-25E  depict several different views of the outer panel  2  of  FIG. 23 .  FIG. 25A  depicts an isometric view of the outer panel  2 ;  FIG. 25B  depicts a front view of the outer panel  2 ;  FIG. 25C  depicts a top view of the outer panel  2 ;  FIG. 25D  depicts a side view of the outer panel  2 ; and  FIG. 25E  depicts a section through the outer panel  2  and shows the W-shape of the example outer panel  2  and some example dimensions.  
      Turning back to  FIGS. 22 and 23 , the example bumper system  10  can further include at least one support  35 . The exploded view of  FIG. 23  depicts the support  35  as four contoured trapezoidal supports  35 A- 35 D. The supports  35 A- 35 D can provide a structure between the inner panel  1  and the outer panel  2 . Although four supports  35  are depicted in  FIG. 23 , in other embodiments there may be more or less supports  35 . In one embodiment, the support  35  comprises a stamped, high strength RA120 steel support. In another embodiment, the support  35  comprises a stamped, high strength SAE 1010 steel support. Other examples and shapes are possible as well. In addition, in one embodiment, each of supports  35 A- 35 D can be attached to the inner panel  1  and the outer panel  2  with 6×30 mm welds ( 3  welds at the inner panel  1  and  3  welds at the outer panel  2 ), for a total of  24  welds for all of supports  35 A- 35 D.  
       FIGS. 26A-26E  depict several different views of the support  35  of  FIG. 23 .  FIG. 26A  depicts an isometric view of the support  35 ;  FIG. 26B  depicts a front view of the support  35 ;  FIG. 26C  depicts a top view of the support  35 ; and  FIG. 26D  depicts a side view of the support  30 .  
       FIG. 27  depicts a cross-section through the bumper system  10  of  FIG. 22 , at a point at or near the center of the bumper system  10  along the width of a vehicle. As shown in  FIG. 27 , the outer panel  2  comprises a W-shaped cross-section and the inner panel  1  comprises a C-shaped section.  FIG. 27  also depicts the profiles of a portion of supports  35 A or  35 B and support  35 C or  35 D.  
      Although not depicted in  FIG. 22  or  23 , this example embodiment of the bumper system  10  can also include crushable modules of the type depicted in  FIGS. 20-21  and as discussed above.  
     Conclusion  
      Several examples of particular embodiments of the present invention have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to these embodiments without departing from the true scope and spirit of the present invention, which is defined by the claims.