Patent Abstract:
A rollover protection device ( 1 ) for a passenger car has a supporting device ( 3 ) that extends vertically when installed properly. A crossmember ( 5 ) is secured on the supporting device ( 3 ) and extends in a lateral direction ( 4 ) when installed properly. The crossmember ( 5 ) is of beam-shaped design and comprises a die-cast, low-pressure die-cast or forged unit ( 6 ).

Full Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 USC 119 to German Patent Appl. No. 10 2016 111 352.2 filed on Jun. 21, 2016, the entire disclosure of which is incorporated herein by reference. 
       BACKGROUND 
     1. Field of the Invention 
       [0002]    The invention relates to a rollover protection device for a passenger car. The rollover protection device has a supporting device that extends in an upward direction when installed properly. A crossmember is secured on the supporting device and extends in a lateral direction when installed properly. 
       2. Description of the Related Art 
       [0003]    Many rollover protection devices for passenger cars have been disclosed in the prior art. For example, DE 102 42 832 A1 shows a three-part rollover bar for motor vehicles. A motor vehicle that turns over will roll on the rollover bar. The rollover bar comprises three bar components, namely two bar leg tubes and a bar head of tubular and U-shaped configuration. The bar leg tubes are screwed to the tubular bar head at associated connection points. The rollover bar and the bar leg tubes can be metal die castings, metal forgings or fibre-reinforced plastic parts. The disadvantage of this prior art is that only a small side region is covered. Moreover, there can be an unfavorable ratio of utilization of material to deformation capacity. 
         [0004]    It is therefore the object of the invention to provide a rollover protection device with improved properties. 
       SUMMARY 
       [0005]    A rollover protection device according to the invention is provided for a passenger car and comprises a supporting device and a crossmember. The supporting device extends in an upward direction when installed properly. The crossmember is secured on the supporting device and extends in a lateral direction when installed properly. The crossmember is of substantially beam that has generous rounded portions, and may comprise a die-cast and/or low-pressure die-cast or forged unit. 
         [0006]    The rollover protection device of the invention has many advantages. For example, the crossmember is of beam-shaped design. Thus, the crossmember can cover a significant width to provide a large contact area, thereby allowing an optimum ratio of utilization of material to deformation capacity. The use of a die-cast unit or a forged unit as a crossmember opens up a large number of design possibilities. Moreover, there is the advantage that the avoidance of sharp edges avoids the need for an additional covering. 
         [0007]    The rollover protection device is suitable for passenger cars, commercial vehicles and especially for cabriolets. There is optimum utilization of the installation space. In all the embodiments, the crossmember may comprise one or more crossmember parts. In this case, each individual crossmember part can be a die casting or a forging. 
         [0008]    The crossmember may comprise at least one recess and, in particular plural recesses. The recesses may extend transversely to a longitudinal extent of the crossmember and can be formed by cold deformation. It is also possible to produce the recesses by a forging method. The recesses also can be produced by a die-casting method or by cold deformation, or can be finish-machined. 
         [0009]    A crossmember provided with plural recesses advantageously combines high stability with a high deformation capacity. As a result, large forces can be absorbed. Considerable energy dissipation by the rollover protection device is made possible while, at the same time, effective protection of the occupants of a passenger vehicle is achieved. 
         [0010]    The recesses may extend substantially in a longitudinal direction of the passenger car. 
         [0011]    The recesses can achieve optimum utilization of material. Minimal and uniform wall thicknesses between the recesses are made possible. It is thereby possible to achieve a continuous and high deformation capacity while, at the same time, high and extremely high forces can be absorbed and dissipated. The total weight can be reduced. Sharp edges are avoided by suitable rounding. 
         [0012]    The individual recesses can be embodied as blind holes or as through holes. In particular, at least two recesses may be arranged directly adjacent to one another. The two adjacent recesses are separated from one another by a single partition wall. 
         [0013]    At least one recess can have a closed bottom. For example, the bottom of a recess can be closed by a cover. However, it is also possible for a recess to receive a continuous bottom at one end during production. The openings of the recesses may be aligned alternately toward the front and toward the rear of the crossmember. Thus, the longitudinal axes of the recesses each may extend approximately parallel to a longitudinal axis of the passenger car. Recesses that are open alternately to the front and to the rear side enable a stable crossmember that can absorb and dissipate enormous forces. 
         [0014]    Each recesses may form a chamber. The chambers can be designed to be open on one side. In particular, a crossmember has a multiplicity of chambers. In one embodiment, the number of chambers is an uneven number. In particular, the number of chambers is between 5 and about 11 and preferably 5 or 6. 
         [0015]    A partition wall may be formed between two chambers. The partition wall may slope relative to the vertical when the cross member is installed properly. A mean angle at the partition wall is preferably between about 0° and 45° relative to the vertical. In particular, the angle is between 5° and 45°. The partition walls alternately may have a particular alignment. Thus, for example, the partition walls can be designed alternately to slope by plus 45° and minus 45° or even by 0° and 45° relative to the vertical. 
         [0016]    The supporting device and/or the crossmember may be adjustable in height. For example, the crossmember can be adjustable in height together with the supporting device. However, the crossmember may be adjustable in height relative to the supporting device. It is then possible to perform adaptation to the respective situation and/or user. 
         [0017]    The crossmember may comprises at least two interconnected crossmember parts. The crossmember parts may be welded to one another. 
         [0018]    At least two crossmember parts may have hook-shaped portions that are interlocked. The crossmember parts can be welded to one another. It is also possible for the crossmember parts to be welded to one another and additionally for each of them to have hook-shaped portions that are interlocked. 
         [0019]    The crossmember may have at least one lateral arched overhang to achieve higher elasticity, improved flexibility and increased contact area. 
         [0020]    The supporting device may comprise at least one vertical member, and a collar may be formed on the crossmember. The collar may fit around the vertical member at the front and rear, and possibly laterally. 
         [0021]    The crossmember may be anchored positively on the supporting device. In this case, the cross member and the supporting device can be connected positively to one another. In particular, the crossmember may engage positively in an inner profile of the vertical member. 
         [0022]    A crossmember that is a forging, die casting of sufficient elongation or a low-pressure die casting provides advantageous rollover protection. Further avoiding sharp edges can eliminate the need for an additional covering. 
         [0023]    The recesses in the crossmember allow optimum utilization of material with minimal and/or advantageous uniform wall thicknesses. This leads to a continuous deformation capacity. The total weight can be reduced. 
         [0024]    Stability and utility can be increased by an alternate wall structure, in which the recesses are alternately open towards the front and the rear. 
         [0025]    Maximum height and maximum width can be achieved. A lateral arched overhang allows better flexibility and a sufficient contact area. 
         [0026]    A collar on the crossmember, at least in the region of an inner profile of the supporting device or of the vertical member, allows improved retention of the crossmember on the supporting device. 
         [0027]    A relatively large number of recesses achieves a considerable weight saving and increased protection for the occupants of a passenger car. 
         [0028]    A positive engagement of the crossmember on the inner profile reduces the number of weld seams. 
         [0029]    Further advantages and features of the invention will become apparent from the illustrative embodiments that are explained below with reference to the figures. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0030]      FIG. 1  is a perspective view of a rear side of a rollover protection device according to the invention. 
           [0031]      FIG. 2  is a schematic vertical section along the line II-II in  FIG. 1 . 
           [0032]      FIG. 3  is a longitudinal section through a lateral region of the rollover protection device  1  shown in  FIG. 1 . 
           [0033]      FIG. 4  is an enlarged detail of an alternative embodiment. 
           [0034]      FIG. 5  is a schematic illustration of another illustrative embodiment of a rollover protection device according to the invention. 
           [0035]      FIG. 6  is a schematic perspective view of a front side of another rollover protection device according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]      FIG. 1  shows a first embodiment of a rollover protection device  1  that comprises a supporting device  3  extending substantially in a vertical direction  2 . The supporting device  3  comprises a vertical member  28  that extends in the vertical direction  2 . A crossmember  5  extends transverse to the supporting device  3  in a lateral direction  4 , and comprises lateral recesses  10  to  12  (nine lateral recesses in this case). 
         [0037]    The recesses  10  to  12  extend substantially parallel to the longitudinal extent of the crossmember and to the longitudinal extent of a passenger car when the rollover protection device  1  and the crossmember  5  are installed in a vehicle. Arched overhangs  27  are provided in the lateral regions, increasing the contact area and also the deformability and load-bearing capacity of the rollover protection device  1 . The radii of the arched overhangs  27  can also be made significantly larger. 
         [0038]    The illustrated crossmember  5  is integral, but can also comprise two different crossmember parts  7 ,  8  that are connected to one another at a suitable fastening. The fastening  17  of the rear window penetration element can also be seen here. A conical washer, for example, can be provided as a glass penetration element. It is also possible for a vertical or substantially vertical wall to be formed centrally in order to support the cone in a vertical direction. 
         [0039]    The illustrated recesses  10  to  12  extend from the rear  16  to the front  15 . An end wall can be provided on the front side  15  to increase stiffness. It is also possible for the recesses to be designed as through holes, given careful rounding. 
         [0040]      FIG. 2  is a schematic cross section that depicts the individual chambers  20  to  22  of the individual recesses  10  to  12 . 
         [0041]      FIG. 3  is an enlarged detail, where the connection of the crossmember  5  or the crossmember part  7  to an inner profile  30  of a supporting device  3  can be seen. The supporting device  3  is welded to the inner profile  30  and thus to the supporting device  3 . In this case, the inner profile  30  is welded to the supporting device  3  by a top weld seam  31 . In addition, an anchoring point  33  can form a positive-locking feature on the supporting device  3  over a certain section. It is also possible for an additional weld seam  32  to be provided. 
         [0042]    The crossmember  5  may have a collar  29 , e.g. an encircling collar  29 , as illustrated in  FIG. 4 , to achieve a positive connection between the crossmember  5  and the supporting device  3  or the inner profiles  30  of the supporting device  3 . The main weld seam  31  can be provided on the encircling collar. 
         [0043]    An alternative embodiment is also possible where the crossmember  5  has, for example, a hook-shaped portion or at least one hook-shaped portion that interacts with a correspondingly matching hook-shaped portion of another crossmember part  7  or  8  so that the hook-shaped portions result in a fastening overall. 
         [0044]      FIG. 5  shows a variant in which a portion  26  increases the extension height. In the retracted state, the installation space can be used over the entire width. 
         [0045]    The crossmember may comprise two crossmember parts  7  and  8  that are fastened to one another at a fastening point  17 . In this case, hook-shaped portions  25  and  26  can engage one another or can optionally be welded to one another to provide the necessary stability. The crossmember  5  is arranged on the supporting device  3 . 
         [0046]    The crossmember  5  in  FIG. 6  has a multiplicity of recesses  10  to  12 . The recesses  10  to  12  extend alternately from the front  15  or from the rear  16  into the crossmember  5 . A single relatively thin wall  23  or  24  exists between two adjacent recesses  10 ,  12 . The alternating arrangement of the recesses  10  and  11  has the bottoms  14  of the respective recesses situated alternately on the front  15  and on the rear  16 . As result, a low weight with a high stability is possible. At the same time, a large width and hence a large contact area optionally can be achieved. 
         [0047]    A reduction in the number of weld seams is optionally possible by anchoring or positive engagement between the crossmember and the supporting device  3  or the inner profile  30  of the vertical member  28 . 
         [0048]    Production as a die casting, low-pressure die casting or as a forging makes possible varied and simple machining, thus allowing a saving of effort and costs. 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
           1  rollover protection device 
           2  upward direction 
           3  supporting device 
           4  lateral direction 
           5  crossmember 
           6  die-cast or forged unit 
           7  crossmember part 
           8  crossmember part 
           9  longitudinal extent of  5   
           10  recess 
           11  recess 
           12  recess 
           13  longitudinal direction 
           14  bottom 
           15  front side 
           16  rear side 
           17  fastening of the rear window penetration element 
           20  chamber 
           21  chamber 
           22  chamber 
           23  partition wall 
           24  partition wall 
           25  portion 
           26  portion 
           27  arched overhang 
           28  vertical member 
           29  collar 
           30  inner profile

Technology Classification (CPC): 1