Abstract:
A bumper with an attachment member to be made thereon for the purpose of mounting the bumper onto longitudinal beams of a vehicle, is such that section walls acting as compressive and tensile struts and a pair of flanking walls joining them form a hollow section. The attachment member is in the form of a hollow section exhibiting at least one side wall and two transverse walls following on therefrom with a length of hollow section with the longitudinal beam. The hollow section is in the form of a push-fit length matching the inner cross-section of the longitudinal beam. The other end region of the attachment member is provided with collar-type parts projecting from their end edges and aligned approximately parallel to the transverse walls. In a use position, the collar-type parts of the attachment member are aligned with the flanking walls of the bumper and are releasably attached to it. The bumper is bolted to the collar-type parts of the attachment member.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates to a bumper with attachment means to be made thereon for the purpose of mounting the bumper onto longitudinal beams of a vehicle, whereby the bumper is such that profiled section walls along with a pair of flanking walls form a hollow section, the section walls of the bumper being spaced apart forming compressive and tensile struts. The attachment means is in the form of a hollow section exhibiting at least one side wall and two transverse walls following on therefrom with a length of hollow support section for attachment to the longitudinal beam. Thereby, the hollow section of the bumper may, if desired at least in the region of the attachment means, be designed such that it is curved i.e. with respect to a transverse plane of the longitudinal axis of the vehicle.  
         [0002]     A bumper with plate-shaped attachments running transverse to the longitudinal axis of its longitudinal beam is described in EP 0 718 158 B1, pointing out that apart from the cross-sectional shape of the bumper also the design of the connection to the longitud-inal beams of the vehicle influences the stability of shape and the capacity to absorb energy of deformation due to impact.  
         [0003]     A variety of attachment means is known for mounting the bumper onto the vehicle—for example from U.S. Pat. No. 5,080,410 or U.S. Pat. No. 4,563,028—these are, however, hardly able to contribute towards improving the shape-stability of a bumper.  
         [0004]     EP 0 894 675 A1 described a bumper arrangement in which the mounting elements of the bumper broaden conically outwards causing their outer walls to lie intimately against the bumper or to converge with it.  
         [0005]     Proposed in DE 298 23 973 U1 are particularly light bumpers which are reinforced with an additional section in load-bearing areas subjected to high loads. Thereby, the reinforcing section may also be a part of a facility for mounting the bumper. In that case the side-walls of the mouting facility expand conically outwards and come into position with the parts of the bumper section.  
       SUMMARY OF THE INVENTION  
       [0006]     In view of the above, the object of the present invention is to provide a bumper of the kind mentioned at the start which exhibits a low weight and a high degree of shape-stability and, at the same time, adequate capacity for absorbing the energy of deformation on impact i.e. creating an efficient energy absorption element. Further, the manufacture and handling of the bumper and the attachment means should be very simple and the longitudinal beam forces should be lower and central.  
         [0007]     The length of hollow support section according to the invention is in the form of a hollow section attachment means with a push-fit length that fits into the inner cross-section of the longitudinal beam. The other end region of the attachment means is provided with collar-like parts that project out from its edges at the end and lie approximately parallel to the transverse walls of the hollow section. In the functioning position, these collar-like parts of the attachment means are aligned with the flanking walls of the bumper and are releasably attached to them, preferably screwed on to them.  
         [0008]     At the other end, the attachment means is likewise releasably secured in the long-itudinal beam—preferably by screws—thus forming an efficient energy-absorbing element.  
         [0009]     This energy-absorbing element can be manufactured in the form of a single chamber section, but is however preferably made in the form of a multi-chamber section. The attachment means should then contain several chambers running parallel to the middle line, which are delimited by both side walls and by the inner plates extending between them. Also it has been found useful to have in the push-fit length a central chamber which is delimited by two outer chambers of smaller volume next to the transverse plates.  
         [0010]     According to a further feature of the invention a longitudinal strip is formed in the side wall of the attachment means at about mid-height—matching the shape of the longitudinal beam—with a breadth that is preferably approximately one third to half the height of the attachment means.  
         [0011]     The longitudinal strip is delimited on both sides by a recess line, which is inclined outwards and upwards and joins up with the plane of the edge strips of the side wall on both sides; the side wall offers therefore a stepped profile comprising three strip-shaped regions. Further, there should be an inner plate extending between both side walls inside the attachment means section on both sides of the longitudinal strip or from the edge strips next to the recess strips. The inner plates usefully run within two planes defined by the collar-like parts. These collar-like parts should be formed by tongue-like lengths that are—as viewed in longitudinal cross-section—curved parts of the transverse plates of the push-fit lengths and should feature holes that accommodate bolts.  
         [0012]     In another version of the collar-like parts, these are channel-shaped parts with upper edges of flanking walls that face away from the middle line of the attachment means; these preferably run into the plane of a side wall, in particular their edge strips. The base of this channel-shaped collar part runs, approximately axially, a distance from its end into a plane that is upwardly inclined and joins up with the transverse plate at the other end.  
         [0013]     It has been found favorable to make both the channel base and the flanking walls double-walled; the channel base should contain lengths of a transverse plate and inner plate that lie one on top of the other, the flanking walls—likewise one on top of the other—preferably contain lengths of the side wall or an edge strip in question.  
         [0014]     According to a further feature of the invention, the end edge of the longitudinal strip projecting axially from both channel-shaped parts of the attachment means is provided on both sides of the middle line with a collar strip which ensures the sideways positioning thereof. This collar strip is arranged at the free end of the longitudinal strip.  
         [0015]     According to another feature of the invention, a transverse axis, which defines the position of the holes in the edge strips of the side walls, is situated a distance from the end edge of the push-fit length.  
         [0016]     According to the invention, an insert element is provided in the outer chamber and features a tube-shaped channel which is to be aligned with the holes in the push-fit length or their transverse axes, said tube-shaped channel penetrating a block-like body which integrally joins up with a face of a base plate of an insert element. This is preferably inserted in a side chamber of the attachment means.  
         [0017]     The base plate terminates at the edge remote from the block-shaped body with an edge channel, which delimits a slit with the surface of the base plate remote from block-shaped body. When the block-shaped body is in the installed position, the edge channel accommodates the abutting inner plate. It has also been found favorable that when the block-shaped body is in the installed position, its end face makes contact with the outer face of a channel-shaped transverse depression on the outside, shape-formed into the transverse plate.  
         [0018]     The attachment means is—as previously mentioned—preferably bolted to the longitudinal beam. For example, the end edge may be inclined at an angle to the middle line of the attachment means and then fixed there by three stud bolts. However, the longitudinal beam may also be attached by means of two or four stud bolts running transverse to the middle line, and the bolts penetrate the section walls of the longitudinal beam and the attachment means.  
         [0019]     It is clear that the attachment means is designed as a straight energy-absorbing element and at the end with both collar-shaped parts fitted over or under the upper and the under flanking walls of the bumper. To that end recesses forming a U-shaped end section are provided in the side walls of the energy-absorbing element.  
         [0020]     At least one of the section walls—preferably however all section walls—of the energy-absorbing element lies against the inner side of the longitudinal beam walls. This allows a push-fit mechanical attachment in the longitudinal beam.  
         [0021]     The cross-section of the energy-absorbing element and the longitudinal beam may—as described above—contain grooves or depressions or the like longitudinal strips for aligning or guiding and fixing the energy-absorbing element when it is pushed into the longitudinal beam. In an end part, at the head of its end length, the energy-absorbing section features a U-shape; its vertical section walls are removed in the end length of the section with the result that the upper and lower side walls of the energy-absorbing element project out beyond the ends of the vertical walls. The upper and lower section wall of the attachment means is—as mentioned—pushed over the upper and lower section walls of the bumper, whereby the end face of the vertical walls of the energy-absorbing element are situated next to the tensile strut of the bumper. The upper and lower walls of the energy-absorbing element projecting over the bumper section walls are attached to the bumper, or upper and lower section walls thereof, by means of one or more bolted connections.  
         [0022]     At the end of the attachment means facing the bumper, the vertical walls of the energy-absorbing element may be removed between the two inner plates. In the end section length, the upper section wall rests against the upper end plate—forming an open U-shaped channel there. The lower section wall in that section end length rests against the lower inner plate—forming a U-shaped channel there. The upper and lower section walls are folded inwards towards the hollow chamber and both form, together with the vertical section walls in the region of the inner plates and with the inner plates, a double-walled length of section. The channel-shaped cross-sections overlap the bumper and are bolted to it. The inwards folding of the upper and lower section walls at the front end section may take place by squeezing, roll-forming, stamping or the like.  
         [0023]     Further advantages, features and details of the invention are revealed in the following description of preferred exemplified embodiments and with the aid of the drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]      FIG. 1 : is a plan view of a bumper with attachment means—different versions at either end of the bumper—for mounting onto a longitudinal beam:  
         [0025]      FIG. 2 : is a perspective view of a part of the bumper with the attachment means shown in  FIG. 1 ;  
         [0026]      FIG. 3 : is a perspective view of another bumper with a profiled element as the attachment means inserted in the longitudinal beam;  
         [0027]      FIG. 4 : is an enlarged perspective view of the profiled element shown in  FIG. 3 ;  
         [0028]      FIG. 5 : is an end view of the profiled element shown reduced in size;  
         [0029]      FIG. 6 : is an enlarged detail from  FIG. 4 ;  
         [0030]     FIGS.  7 ,  10 : show two other versions of the detail shown in  FIG. 6 ;  
         [0031]     FIGS.  8 ,  9 : are a front view and plan view, respectively, of the detail shown in  FIG. 7 ;  
         [0032]      FIGS. 11, 12 ,  15 : are perspective views of a part of a longitudinal beam with attachment means secured in place;  
         [0033]      FIGS. 13-14 ,  16 : in each case a part of a sectioned longitudinal beam with attachment means inserted in it; and  
         [0034]      FIG. 17 : is an enlarged front view of a channel-shaped part of the attachment means, indicated in FIGS.  11  to  15 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     A bumper  10  made from an extruded aluminium alloy—for a private car which for reasons of clarity is not shown here—features, as shown in  FIG. 1 , a box-shaped hollow section  12  with two section walls  14 ,  16  that are spaced a distance a apart and are joined by transverse or flanking walls  18 . The hollow section  12  is aligned to a transverse plane E running at a right angle to the longitudinal axis A of a vehicle, and curved with respect to that transverse plane E, equally and symmetrically on both sides of the vehicle longitudinal axis A. A distance k from the plane E to the interception of the longitudinal axis A with the hollow section  12  defines the extent of curvature. When installed, the outer section wall  14  facing away from the transverse plane E forms an outer or compression strut which receives the forces of impact, while the inner section wall  16  forms an inner or tensile strut.  
         [0036]     The bumper  10  is aligned with longitudinal beams  30  of a vehicle, which run parallel to the longitudinal axis A of the vehicle. They are made up of two parallel side walls  34  and transverse walls  36  joining them, which define an interior  32  of the longitudinal beams  30 .  
         [0037]     Indicated in  FIG. 1  close to the right end edge  20  of the hollow section  12  is a tube-like deformation facility  40  comprising a section piece which makes contact with the inner section wall  16  at one end and, at the other end is aligned with a push-fit length  42  of the longitudinal beam  30 . The deformation facility  40  is likewise made from an extruded light weight aluminium alloy and, at the end abutting the bumper  10 , is cut at an angle. The resultant inclined end  44  of the section piece defines the angle w of e.g. 10° the bumper  10  makes with the transverse plane E.  
         [0038]     Another mode of connection of the hollow section  12  to the longitudinal beam  30  is sketched out in  FIG. 1  at the left end of the bumper  10  and shown in greater detail in  FIG. 2 . Here it is clear that the section wall  14 —serving as outer strut and wave-shaped in cross-section—exhibits wing-shaped wall parts in the form of edge strips  15 ,  15  t that project out beyond the transverse or flanking walls  18 . Also to be seen in  FIG. 2  is that an edge strip  35  on the side wall  34  of the longitudinal beam  30  likewise extends beyond the outer face of the transverse wall  36 . The second side wall  34  is for reason of clarity not shown here.  
         [0039]     Provided in the interior  22  of the hollow section  12  is an integral transverse wall  24  running parallel to the section walls  14 ,  16 , joining the flanking walls  18  and featuring middle walls  26  joining up with the section walls  14 ,  16 . These middle walls  26  are offset with respect to each other.  
         [0040]     In this case the connection between the hollow section  12  and the longitudinal beam  30  is made via a mounting bracket  46  in the form of a hollow extruded aluminium alloy section of breadth b e.g. of 55 mm and height h 75 mm. A push-fit length  48 , which is approximately rectangular in cross-section—featuring two parallel side walls  49 ,  49   a  with transverse side walls  50  of the hollow section of the bracket  46  joining them—is aligned with the longitudinal beam  30  of height e and screwed into place there. The push-fit length  48  also features a curved length  52 . The right hand side wall  49   a  is curved out from the longitudinal axis M 1 , i.e. in  FIG. 2  towards the right, and the other side wall  49  is curved towards its end such that at the end both side walls  49 ,  49   a  lie against each other and each of the transverse walls  50  is folded approximately in the middle. Thereby, the inner curvature runs the same as the outer face of the inner section wall  16  of the hollow section  12 , i.e. they run together on a parallel at the above mentioned angle w to the transverse plane E.  
         [0041]     The double layered flanges  54  of the resultant channel-like curved length  52  are penetrated in the region of holes—not shown in the drawing—by screws  56  or like connecting means which also engage in holes in the flanking walls  18  of the bumper. Corresponding holes for connecting means  56   a  are provided in the push-fit length  48  of the mounting bracket  46 . These connecting means  56   a  are situated in openings  38  in the longitudinal beam  30 .  
         [0042]      FIG. 3  shows a bumper  10  with the above mentioned holes  28  in its flanking walls  18 . Also to be seen here is the end region of a longitudinal beam  30  a distance f from the bumper  10 . Shape-formed into both side walls  34 , at about mid-height, are longitudinal strips  33  delimited by recess lines  35 . The breadth g of the longitudinal strips  33  is equal to about half the section height e.  
         [0043]     Inserted into the free end of the longitudinal beam  30  is a length of hollow section in the form of a push-fit length  42  of a deformation facility or section element  41 , the approx. rectangular cross-section of which is defined by side walls  58  and transverse walls  60 . Each side wall  58 —corresponding to the shape of the side wall  34  of the longitudinal beam  30 —contains at about mid-height a shape-formed longitudinal strips  59  of depth q. The longitudinal edges of each of the longitudinal strips  59  are formed by recess lines  57  which are curved outwards—upwards—and continue into a strip  58   a  of the side wall  58 . In section element  41 , parallel to transverse walls  60  and running a short distance from both recess lines  57  in the side wall  58 , are inner plates  62 , the transverse edges  63  of which form transverse lines in the end edge  64  of section element  41  and delimit two side chambers  67  on either side of a central chamber  66  in the middle of the section element  41 .  
         [0044]     Provided on both sides of the integral longitudinal strip  59 , in the side wall  58  is a hole  68  of diameter d for insertion of a connecting pin which penetrates both the longitudinal beam and the section element  41 . Correspondingly, holes  37  are provided in the side walls  34  of the longitudinal beam  30 .  
         [0045]     Shown in  FIG. 3 , close to the end edge  31  of the longitudinal beam  30  in each of the transverse walls  60  of the section element  41 , is a transverse depression  69  which is approximately semi-circular in cross-section and runs parallel to an axis Q of one of the holes  37 ,  68 . The distance z of the axis Q from the end edge  64  of the section element  41  is indicated in  FIG. 4 .  
         [0046]     The end height h 1  of the end of section element  41  facing the bumper  10  matches the free inner height n of the bumper  10 . The end height h 1  is defined by the outer faces of a pair of collar-shaped plates  70  as end regions of the transverse walls or plates  60 , which project beyond end area  65  of the section element  41 —running to the right in  FIG. 3 ,  4 —and are mated with the transverse plate  60  in question by means of a curved tongue-shaped length  72 , as viewed in the longitudinal cross-section. Also as viewed in longitudinal cross-section it can be seen that lengths  74  of the transverse plate  60  are bent towards the middle axis m of the section element  41 . These lie against the outer face of the neighboring inner plate  62 . The insides of both collar-shaped plates  70  fit by virtue of shape onto the transverse walls  18  of the bumper  10  and are joined to them by means of screws  56 , which pass through holes  55 ,  55   a .  
         [0047]     Inserted between the above mentioned inner plate  62  and the neighboring transverse wall  60  of the section element  41 , in a side chamber  67 , is a special insert element  80  which is sketched in detail in  FIG. 6 . When installed in place, the base plate  76  of the insert  80  lies against the inner plate  62  of the section element  41 . The base plate  76 —an integral part of a block-shaped body  82 —projects out tangentially from that block  82 . A tube-shaped channel  84  of diameter d, which corresponds to that of the holes  37 ,  68 , is centered along the transverse axis Q, when an edge channel  78  in the base plate  76  engages the end edge  63  of the inner plate  62  making contact with this surface  77 , by means of a slit  79  which is delimited on one side by, and parallel to, the surface  77 . The—in  FIG. 6  right—partially circular-shaped, curved end face  83  of the block-shaped or tube-like body  82  lies against the outer face of the channel-shaped depression  69  in the neighboring transverse plate  60 .  
         [0048]     Another version of an insert element  80   a  as shown in  FIG. 7 — 9  contains a channel  85  which is oval in cross-section of breadth b 2  of 14 mm and height h 2  of 18 mm in the tube-like body  82   a  of breadth c of 26 mm and height i of 21 mm. The thickness y of the base plate  76  is in this case 3 mm, while the height s of the slit  79  at the edge channel  78  is 2.2 mm; its shorter flange  75  has a length y 1  of 7 mm and an overall length n 1  of the insert element  80   a  of approx. 49 mm and breadth b 1  of approx. 55 mm.  
         [0049]     The insert  80   b  shown in  FIG. 10  comprises a tube-like body  82   a  with the specific dimensions of that in  FIG. 8 , i.e. it has no base plate.  
         [0050]     FIGS.  11  to  13  show a section element  41   a  with an end edge  64   a  inclined at an angle t of about 70° to the middle line M. This is secured in place by three stud bolts  96  with nuts  98  at the ends. At the free ends project two integral channel-shaped parts  86  which are screwed onto the bumper  10 . Both flanking walls  87  of channel-shaped parts  86  of collar length k 1  run into the plane of the edge strips  58   a  a distance z 1  from the recess lines  57 , the upper edges  88  of which are a distance z 2  from the surface  61  of the trans-verse plate or transverse wall  60 . These flanking walls  87  are shape-formed towards the middle line M on a channel base  89 , which joins up at the rear plane  90  with the transverse plate  60 ; this can be seen particularly well in  FIG. 12, 15 . The sloping plane  90  begins a distance f 1  from the end  91  of the channel  86 . Also, an integral narrow collar strip  94  is provided at the free end edge  59   e  of each longitudinal strip  59 .  
         [0051]     In particular in  FIG. 17  it can be seen that the internal channel part  86  has a double wall—as seen in cross-section. The channel base  89  is formed towards the interior  92  by a shape-formed length  60   a  of the transverse plate  60 , which lies on a length  62   a  of the inner plate  62 . Both flanking walls  87  bordering the channel base  89  are formed by two layers of a length  58   b  of the edge strip  58 .  
         [0052]     The section elements  41   b ,  41   c  in  FIGS. 14, 15  are secured—with end edge  64  perpendicular to the longitudianl axis or middle line M—by three stud bolts  96 , and the section element  41   d  in  FIG. 12  with four stud bolts  96 .  
         [0053]     The bolted connection formed by the stud bolts  96  penetrates preferably the entire section cross-section and is such that the head  97  of the bolt—with or without washer—makes contact with a first section wall  34  and its nut  98 —with or without washer—makes contact with one of the first, essentially opposite second section wall  34  of the longitudinal beam  30 .  
         [0054]     Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become more apparent to those skilled in the art. It is preferred, thereof, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.