Abstract:
An arrangement for fastening a bumper to a vehicle includes a deformation organ having one end for attachment to the bumper, and another end for sliding into a side member. The insertion section includes an inner wall which is stretchable when subjected to a tensile force. For elongating the inner wall, a material strip is received in a receiving space and equipped with a threaded breakthrough, which is aligned with a breakthrough of the adjacent transverse wall for receiving a tensile screw. The tensile screw extends through a breakthrough in a side member and exerts a force which elongates the inner wall. This initially provides a loose sliding-in of the insertion section in the side member and, following stretching of the inner wall, a tight seat of the insertion section in the side member.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation-in-part of U.S. patent application Ser. No. 12/298,717 filed Oct. 27, 2008, which is a U.S. National-Stage entry under 35 U.S.C. §371 based on International Application No. PCT/EP2007/003375, filed Apr. 17, 2007, which was published under PCT Article 21(2), and claims priority to German Application Nos. 102006019654.6, filed Apr. 25, 2006, and claims priority to German Application No. 102006040178.6, filed Apr. 25, 2006, which are all hereby incorporated in their entirety by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to an arrangement for fastening a bumper to side members of a vehicle. 
       BACKGROUND 
       [0003]    EP 1 079 992 B1 discloses a device in a vehicle for absorbing impact energy with a fastening member for a bumper element on the vehicle frame; that fastening member has at least two walls running in longitudinal direction, which are provided with openings to receive penetrating pins. During a collision impact or a vehicle collision, the pins are moved along predetermined lines relative to the respective energy-absorbing walls of the fastening member in order to enlarge those openings subject to the formation of strips. To this end, the pins are designed so that they shear off the wall material in order to enlarge or elongate the openings in the energy-absorbing wall. 
         [0004]    EP 0 718 158 B1 discloses a bumper with plate-like holders crossing the longitudinal axis of its side member. In addition to the cross-sectional shape of the bumper, the configuration of the connection to the vehicle side member also influences its shape retention and its compensation ability with respect to the impacting deformation energy. 
         [0005]    U.S. Pat. No. 5,080,410 or U.S. Pat. No. 4,563,028 disclose fastening the bumper to the vehicle using a multiplicity of holders which, however, do not contribute to the improvement of the shape retention of a bumper in the event of an impact. 
         [0006]    EP 0 894 675 A1 discloses a bumper arrangement, wherein the holding elements of the bumper widen conically and the outer walls of which hug the profile wall of the bumper or merge with the latter in this way. 
         [0007]    DE 298 23 973 U1 discloses particularly light bumpers which are reinforced in severely loaded regions by an additional profile. The reinforcement profile can also consist of a holding device for the bumper. In the latter case, the side walls of the holding device widen conically and come to bear against the profile strips of the bumper. 
       SUMMARY 
       [0008]    The present disclosure provides an arrangement for fastening a bumper which, with low weight has a high degree of shape retention with adequate compensation capability for the impacting deformation energy, so that an efficient energy absorption element is created. Manufacture and handling of the arrangement are to be very simple and the side member forces lower as well as central. In addition, the inaccuracy of the components during the joining process is to be compensated and a relatively large gap between crash box and side member is to be closed. 
         [0009]    In addition, the present disclosure includes all combinations of the features disclosed in the description, the drawings, and/or the claims. In the case of stated designation regions, values located within and proximate the mentioned limits are to be also contemplated by the present disclosure and are variously employable as limit values. 
         [0010]    According to an embodiment, the arrangement includes a deformation organ which on the one end is provided for attachment to the bumper, and on the other end includes an insertion section for sliding into one of the side members, wherein the insertion section comprises transverse walls and an inner wall molded onto the transverse walls on both ends which are channel-like in cross section and is stretchable when subjected to a tensile force acting on the transverse walls. This makes possible initially a simple sliding-in of the insertion section in the side member with play and, subsequently, following stretching of the inner wall, a tight seat of the insertion section in the side member. 
         [0011]    In accordance with an embodiment, the inner wall can be arranged between the side walls of the insertion section connecting the transverse walls. 
         [0012]    Preferentially, the transverse walls are connected to the side walls via corner regions curved in the manner of a pitch circle. 
         [0013]    For elongating the inner wall, a material strip can be provided which is received in a receiving space of the insertion section and equipped with a threaded breakthrough, which is in alignment with a breakthrough of the adjacent transverse wall in order to be able to receive a tensile screw. 
         [0014]    In that the tensile screw furthermore extends through a breakthrough of the one side member it is able to exert the force necessary for elongating the inner wall. 
         [0015]    Breakthroughs for two tensile screws opposite each other are preferentially arranged on both sides of a center line of the insertion section and may have a common center axis. 
         [0016]    The deformation organ ( 40 ) can be practically produced from an extruded profile element ( 42   a ), more preferably from light metal. 
         [0017]    The present disclosure further provides an arrangement having a bumper, side members and a deformation organ, which on the one end is attached to the bumper and on the other end includes an insertion section slid into the side member and which is obtained out of the arrangement described above through the pulling of the transverse walls of the insertion section against transverse walls of the one side member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and: 
           [0019]      FIG. 1  is a top view of a bumper having holders—formed differently on both ends of the bumper—for connection to a side member; 
           [0020]      FIG. 2  is an oblique view enlarged with respect to  FIG. 1  of a part of the bumper with holder; 
           [0021]      FIGS. 3 and 4  illustrate cross sections through a side member with a profile element as holder inserted in one side member prior to being pulled apart; and 
           [0022]      FIGS. 5 and 6  illustrate cross sections through the side member after being pulled apart. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description. 
         [0024]    A bumper  10  extruded from an aluminum alloy of a passenger car (not reproduced for reasons of clarity) has a box-shaped hollow profile  12  according to  FIG. 1  with two profile walls  14 ,  16  running at a spacing a relative to each other, which are connected through two transverse or flank walls  18 . The hollow profile  12  is assigned to a transverse plane E—running at a right angle to the vehicle longitudinal axis indicated at A—and on both sides of the vehicle longitudinal axis A forming a symmetry plane here and evenly curved towards that transverse plane E; towards the latter, the hollow profile  12  determines a curvature dimension k in the longitudinal axis A located in the curvature zenith. When installed, the outer profile  14  facing away from the transverse plane E forms an outer or pressure belt capable of absorbing shock forces. The other—inner—profile wall  14  forms an inner or tension belt. 
         [0025]    The bumper  10  is assigned to a pair of vehicle side members  30  of rectangular cross section preferably formed of steel, which run on both sides parallel to the vehicle longitudinal axis A. These, in turn, may be assembled from two parallel side walls  34  and transverse walls  36  connecting these, which delimit an interior space  32  of the vehicle side member  30 . 
         [0026]    Near the right face edge  20  of the hollow profile  12 , a tubular deformation organ  40  of a profile piece is indicated on the right hand side in  FIG. 1 , which on the one end is attached to the inner profile wall  16  and, on the other end, is assigned with an insertion section  43  to the vehicle side member  30 . The deformation organ  40  (also called a crash box) may likewise be produced from a profile element extruded from light metal and on the end facing the bumper  10  beveled to the center line M of the deformation organ  40 ; the oblique edge  40  of the profile element  40  so created defines an angle w of, for example, 10° with the transverse plane E. 
         [0027]    Another configuration of the connection of the hollow profile  12  to the vehicle side member  30  is shown in  FIG. 1  on the left end of the bumper  10  and evident from  FIG. 2 . The profile wall  14  serving as outer belt—and designed wave-like in cross section—engages over both transverse of flank walls  18  with wing-like wall sections as edge strips  15 ,  15   t.  As seen in  FIG. 2 , the side wall  34  of the vehicle side member  30  protrudes over the outer surface of the attached transverse wall  36  with an edge strip  35 . The second side wall  34  is not drawn in here for the sake of clarity, its fastening region is illustrated in hashed section lines. 
         [0028]    In the profile interior space  22  of the hollow profile  12  a transverse wall  24 —directed parallel to the profile walls  14 ,  16 —is provided unitarily with the profile walls  14 ,  16  and the flank walls  18  connecting these, each with a middle wall  26  running between the transverse wall and the profile walls  14 ,  16 . These middle walls  26  may be offset in height and side relative to each other. 
         [0029]    The connection of the hollow profile  12  to the vehicle side member  30  may be established by a holding member  46  configured from a hollow profile which, in turn, may be extruded from an aluminum alloy of a width “b” in the range of, for example, 55 mm, and a height “h” in the range of, for example, 75 mm. On its insertion section  48  assigned to the vehicle side member  30  of profile height e or its face edge  31  and screwed together in said vehicle side member of approximately rectangular cross section—of two parallel side walls  49  and transverse walls  50  of the hollow profile of the holder  46  connecting these—is followed by a curvature section  52 . In  FIG. 2  right side wall  49  is curved outward—i.e., in this case out of the longitudinal axis M 1  of the insertion section  48  to the right—and the other side wall  49  towards the end led against the former in such a manner that both side walls  49  lie on top of each other and each of the two transverse walls  50  is folded approximately in its longitudinal middle. The inner curvature contour runs corresponding to the outer surface of the inner profile wall  16  of the hollow profile  12 , i.e., it encloses the angle w with “a” being parallel to the transverse plane E. 
         [0030]    Double-layered legs  54  of the channel-like curvature section  52  so created are penetrated in the region of breakthroughs of screws  56  or similar connecting organs (elements)—not shown in the drawing—which additionally engage in breakthroughs of the flank walls  18  on the bumper side. Corresponding breakthroughs for connecting organs  56   a  are provided in the insertion section  48  of the holding member  46 . In an embodiment, these connecting organs  56   a  are mounted in the vehicle side member  30  in breakthroughs  38 . A profile element or a crash box  42   a  of substantially rectangular cross section of two side walls  45   a  and two transverse walls  42   a  of wall lengths “c”, “f” connecting these is inserted in the side member  30  of  FIGS. 3 and 4 . The transitions of the side walls  45   a  to the transverse walls  47   a,  are formed by corner regions  45   e  which may be curved in the manner of a pitch circle. 
         [0031]    In order to simplify the sliding-in process, the side walls  45   a,    47   a  each run at a spacing “g” to the neighboring inner surface  48  of the side walls  34  and the transverse walls  36  of the side member  30  subject to the formation of gap spaces  41  and  41   q.    
         [0032]    In the profile element  42   a,  on the inside of each side wall  45   a,  an inner wall  51   a  is placed in front which is molded onto the transverse walls  47   a  on both ends and spaced from the latter offers a channel-like cross section. A receiving space  55 —determined by the channel region  53  of the inner wall  51 —is located on each molded-on region for a material strip  60  of hexagonal solid cross section mounted therein. The latter is equipped with a thread breakthrough  58  which is in alignment with a breakthrough  57  of the adjacent transverse wall  47   a  and the breakthrough  38  in the side member  30 . 
         [0033]    In  FIG. 4 , the center line “M” of the profile element  42   a  is in alignment with the longitudinal axis “B” of the surrounding side member  30 . The transverse walls  47   a  of the profile element  42   a  standing at that spacing “g” to the inner surfaces  28  of the longitudinal profile  30  noticeably run axially parallel. The aligned breakthroughs  38 ,  57 ,  58  of the one system side determine a common center axis Q with the breakthroughs  58 ,  57 ,  38  of the other system side and each receive a tensile screw  56   b  indicated in  FIG. 4 , which towards the end is screwed together with the thread  59  of the thread breakthrough  58  and subject to the deformation of the profile element  42   a  pulls the transverse wall  47  of said profile element including the material strip  60  up against the adjacent side wall  34  of the side member  30 . This deformation produces the profile element  42  shown in  FIGS. 5 and 6 . 
         [0034]    Instead of those bent inner walls  51   a  shown in  FIG. 3 ,  FIGS. 5 and 6  illustrate, towards the side walls  45  and towards the middle axis “Q”, inner walls  51  of profile element  42  axially parallel in cross section resulting from the completed bending process so that the regions  47  of the transverse walls lifted because of this directly bear against the inner surfaces  28  of the side member  30  and their outer spacing “c 1 ” approximately corresponds to the width of the profile element  42 , which according to  FIG. 6  illustrates a curvature region  47   k  reduced to the wall length “c” mentioned in  FIG. 3 . Thus, within the side member  30 , an insertion section  62  of axial length “z” bearing against said side member on both sides is created. The two side walls  45  parallel to the center axis “Q” which with relative to  FIG. 3  more stretched corner regions  45   g  merge with the adjoining transverse walls  47 , retain the gap spacing “g” to the inner surface  28  of the side member  30 . 
         [0035]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.