Abstract:
A hollow elongated support structure designed in particular to support a motor vehicle fittings located at right angle with the instrument panel, the ends of the structure ( 10 ) including an end flange ( 100 ) arranged transversely for fixing and/or maintaining the instrument panel itself, and/or for fixing the hollow support structure ( 10 ) to the vehicle body: each end flange ( 100 ) is integral with a plastic end cap ( 20, 30 ) inserted into the support structure ( 10 ), at the ends thereof with which it is integral.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is the national stage of International Application PCT/FR99/02210 filed on Sep. 16, 1999, which designated the United States of America. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an elongate hollow support structure intended in particular to support the equipment units in the vicinity of the dashboard of an automobile vehicle. 
     BACKGROUND OF THE INVENTION 
     This kind of support structure is well known in the art; usually referred to as a crossmember, it is made of metal and disposed transversely to the longitudinal axis of the vehicle at the front end of the passenger compartment and supports equipment units such as the dashboard itself, the steering column, the heater or air-conditioner, the air bag(s) and other equipment. 
     The crossmember is generally fixed to the frame of the body of the vehicle near its ends. To this end, members are attached, in particular welded, to its ends, as described in the document EP-A-694 465, U.S. Pat. No. 4,826,235 or U.S. Pat. No. 5,387,023, for example. This method is costly. 
     It has also been proposed to fasten to each end of the beam structure a transverse flange for fixing and/or retaining the dashboard itself, the contour of said flanges matching the section of the dashboard or even its trim. 
     Until now the above kind of flanges have been welded to the support structure. Apart from the fact that this operation is difficult and costly, it does not facilitate storing or transporting structures equipped in this way to the place where the vehicles are assembled, especially as said flanges can be large; moreover, they are fragile and can be deformed during storage or transportation. 
     SUMMARY OF THE INVENTION 
     The present invention provides an elongate hollow support structure intended in particular to support the equipment units of an automobile vehicle in the vicinity of its dashboard, the ends of said structure including a transverse end flange for fixing and/or retaining the dashboard itself and/or for fixing the hollow support structure to the body of the vehicle, said support structure having a lower unit cost than prior art support structures. 
     According to the invention, a support structure of the above kind is characterized in that each end flange is fastened to a plastics material plug inserted into said support structure, to the ends of which it is fastened. 
     The plug advantageously includes a baseplate from which protrudes a block, said baseplate projecting relative to the block to define a peripheral transverse rim. 
     If the section of the structure delimits a plurality of closed spaces, a plurality of blocks preferably protrude from the baseplate and each of said blocks is adapted to be mounted in one of said spaces. 
     The plug is advantageously adapted to be force-fitted into said structure. 
     If the structure includes transversely facing openings for fixing members for fixing the structure to the body or the plug to the structure, to pass through then the plug has a passage through it aligned with said openings. 
     The openings and the passage preferably have an oblong section. 
     The passage is advantageously bordered by a metal tube. 
     The plug is preferably molded over the metal tube. 
     The inside surface of one or both ends of the hollow support structure adapted to receive a plug is preferably provided with means for facilitating aligning the passage(s) with said openings. 
     The inside surface of the ends of the structure is advantageously not a surface of revolution. 
     The inside surface of one or both ends of the hollow support structure is preferably a surface of revolution and has a notch at the end adapted to cooperate with a raised portion on the outside surface of the plug(s). 
     The plug is advantageously fastened to the end flange by means of a bracket having rims attached, for example welded, to the end flange. 
     The plug is preferably a block which has a groove in which the bracket locates, straddling the block. 
     The plug is advantageously a block molded onto the bracket. 
     The bracket is advantageously generally U-shaped and the passage in the plug is advantageously parallel to the flanges of the bracket. 
     The bracket is advantageously generally U-shaped and the passage in the plug is advantageously perpendicular to the flanges of the bracket which are advantageously provided with openings aligned with the end of the passage. 
     Alternatively, the end flange has an anchorage over which the plug is molded; the anchorage is obtained by cutting and pressing; the anchorage is obtained by cutting and bending lugs. 
     The openings of the structure are advantageously obtained by hydroforming and the block advantageously has a lateral notch for avoiding a tongue resulting from hydroforming when mounting the plug in the structure. 
     To explain the purpose of the invention better, embodiments of the invention shown in the appended drawings by way of purely illustrative and non-limiting example will now be described. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is an elevation view of a support structure according to the invention; 
     FIG. 2 is a plan view of the support structure from FIG. 1; 
     FIG. 3 is a view of the support structure without its flanges in section taken along the line III—III in FIG. 1; 
     FIG. 4 is a view of the support structure without its flanges in section taken along the line IV—IV in FIG. 1; 
     FIG. 5 is a partial elevation view of a flange included in the support structure shown in FIGS. 1 to  4  and equipped with a plug; 
     FIG. 6 is a view in the direction of the arrow VI in FIG. 5; 
     FIG. 7 is a view in section taken along the line III—III in FIG. 1; 
     FIG. 8 is a partial elevation view of a flange included in the support structure from FIGS. 1 to  4  and equipped with a different plug; 
     FIG. 9 is a view in the direction of the arrow IX in FIG. 8, 
     FIG. 10 is a view in section taken along the line IV—IV in FIG. 1; 
     FIG. 11 is a perspective view of an end flange equipped with a different plug; 
     FIG. 12 is a partial plan view of the plug in the direction of the arrow XII in FIG.  11  and to a larger scale; 
     FIG. 13 is a view in the direction of the arrow XIII in FIG. 12; 
     FIG. 14 is a part-sectional view showing a different embodiment of the plug shown in FIGS. 11 to  13 ; 
     FIG. 15 is a view in the direction of the arrow XV in FIG. 14 showing only the block; 
     FIG. 16 is a view in section taken along the line XVI—XVI in FIG. 15; 
     FIGS. 17 and 18 are analogous to FIGS. 15 and 16 and show a different embodiment of the invention; and 
     FIGS. 19 and 20 each show in perspective one embodiment of an end flange provided with an anchorage adapted to have a block of plastics material molded over it. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 to  4  show a support structure  10  obtained by assembling a globally rectangular section tube  12  extending the entire length of the structure from its driver end  14  to its passenger end  15 ; starting from the driver end  14  of the structure  10 , and over almost half the length of the structure  10 , the tube  12  has a rectangular section with rounded edges; beyond a connection area, and as far as the passenger end  15 , its section is larger and practically square. A tube of the above kind is conveniently obtained by hydroforming a cylindrical tube to a constant perimeter. A hydroforming process of the above kind is described in the document EP-A-0 294 034 in particular. 
     At the driver end  14 , a U-shaped beam  11  is welded to the tube  12 , which is partly engaged between the flanges of the U-shape of the U-shaped beam  11 , which extends from the driver end  14  along the smaller section part of the tube  13  and is then joined to its larger section part, whose section is nevertheless smaller than that surrounded by the beam  11 . This produces a support structure  10  of high inertia, including in the area near the driver end which supports the steering column. The reference numbers  13  indicate locations for fixing equipment units in the vicinity of the dashboard; they are generally plain or threaded holes with or without a flange. 
     The support structure  10  has at each end one or more pairs of facing transverse openings to accommodate fixing members such as bolts for fixing the support structure  10  to the frame of the body of the vehicle; two pairs of openings are provided at the driver end  14 , one pair of openings  16  in the walls of the beam  11  and the tube  12  and one pair of openings  18  in the walls of the beam  11  only; a single pair of openings  17  is provided at the passenger end  15 ; all the above openings are preferably oblong to allow for variations in the dimensions of the body. 
     The support structure  10  according to the invention has a flange  100  at each end fitted with a plastics material plug. 
     FIGS. 5 and 6 show only the plug for the driver end  14  of the support structure  10 ; the plug  20  has a plane baseplate  24  from which emerge two blocks  21  and  22  separated by a gap  23 . 
     Each block  21 ,  22  has a respective passage  26 ,  28  through it whose section corresponds to that of the openings  16 ,  18 ; each passage  26 ,  28  is bordered by an oblong metal tube  27 ,  29  around which the blocks  21  and  22  are molded. The block  21  is adapted to be force-fitted into the tube  12  and the block  22  is adapted to be force-fitted into the closed space of the beam  11  delimited by the tube  12 ; forming bosses (not shown) on the peripheral surfaces of the blocks  21 ,  22  enables the peripheral surfaces of the blocks  21 ,  22  to deform slightly to accommodate variations in the dimensions of the blocks; the length of the oblong tube  27  corresponds to the distance between the inside walls of the tube  12  defining the openings  16  and the length of the oblong tube  29  corresponds to the distance between the inside walls of the flanges of the U-shaped beam  11 ; the two blocks  21 ,  22  naturally share the baseplate  24 , which joins them together, the whole being molded in one piece; the width of the gap  23  corresponds to the thickness of the wall of the tube  12  inside the beam  11 , which it is adapted to receive. The baseplate  24  projects relative to the blocks  21 ,  22  to define a peripheral transverse rim  25 . 
     Accordingly, it will be clear that when the plug is force-fitted into the beam structure  10  it is fastened to it and forms an integral part of said structure, requiring neither gluing nor welding; as shown in FIG. 7, when it is in place the passages  26 ,  28  are perfectly aligned with the respective transversely facing opening  16 ,  18  and the plug  20  is positioned in the support structure  10  by coming into abutting engagement against the edge of the rim  25  defined around the blocks  21 ,  22  by the baseplate  24  at the end of the support structure  10 ; note that the ends of the oblong tubes  27 ,  29  are then in line with, and virtually in contact with, the walls of the tube  12  and the beam  11  incorporating the openings: the oblong tubes  27 ,  29  act as spacers preventing these walls from buckling on tightening up the fixing members for the support structure  10  that pass through the passages  26 ,  28 ; thanks to the invention, the oblong tubes are perfectly positioned, in an economical manner, without it being necessary to use a template; also, the passages  26 ,  28  guide the fixing members when the support structure  10  is mounted on the frame of the body. 
     FIGS. 8 to  10  are respectively analogous to FIGS. 5 to  7  that have just been described, but show the plug  30  at the passenger end  15  of the support structure  10 ; unchanged relative to the plug  20  in all other respects, the plug  30  comprises only one plastics material block  31  upstanding from a baseplate  34  defining a rim  35  around it and only one passage  36  bordered by an oblong tube  37 ; the block  31  matches the section of the tube  12  at the passenger end  15 . 
     In the embodiments that have just been described the passages  26 ,  28 ,  36  are bordered by respective oblong tubes  27 ,  29 ,  37 ; in an embodiment which is not shown the oblong tubes are dispensed with; the plastics material of the plugs can be polypropylene, polyvinyl chloride or polyethylene. 
     The plugs described hereinabove are connected to the end flanges  100  by any appropriate means. 
     In FIGS. 11 to  13  the plug  40 , which has a circular section passage  46  through it, consists of a block  41  of plastics material molded over a generally U-shaped metal bracket  42  having a core  43  and two flanges  44  embedded in the block  41 ; the flanges  44  of the bracket  42  are extended externally of the block  41  by coplanar rims  45  parallel to the core  43  and extending in opposite directions; the plug  40  is fixed to the flange  100  by means of the rims  45 , for example by spot welds  47 . 
     Accordingly, the plug  40  equipped with the flange  100  can be inserted into the support structure  10  on the vehicle assembly line just before the structure is fixed to the frame of the body and the drawbacks referred to hereinabove are avoided. 
     FIGS. 14,  15  and  16  show a plug  50  analogous to the plug  40  described hereinabove but in which the bracket  42  does not have the plastics material block  51  molded over it; the block has at the periphery of three of its sides a groove  53  whose width corresponds to that of the bracket  42 ; the U-shape of the bracket  42  fits in the groove  43 , thereby straddling the block  51 , and the bracket is then fixed to the flange  100 ; the block  51  is retained laterally by means of the groove  53 ; note also that the cross section of the plastics material block  51  is globally circular, the plug being designed to be fitted to a tubular section support structure  10 ; thus the invention applies to any kind of structure, regardless of its section. 
     In the embodiments described with reference to FIGS. 11 to  16 , the passage  46  or  56  is parallel to the flanges of the bracket  53 ; in a different embodiment, not shown, the passage is perpendicular to the flanges of the bracket, i.e. parallel to the core of said bracket, and in this case the flanges of the bracket incorporate openings aligned with the ends of the passage  46 ,  56 . 
     Support structures like the support structure  10  can be obtained by hydroforming; the hydroforming process can also be used to form the openings  16 ,  17  or  18 : in this case, as is known in the art, the material displaced to form the openings is not separated from the structure but remains attached to it on the inside like a tongue and perpendicular to the wall in which the corresponding opening is formed; in this case it is advantageous to provide in the plastics material block a lateral notch  54  (see FIGS. 17 and 18) to avoid these tongues during mounting of the plug in the support structure. 
     FIG. 19 shows an end flange  100  in which an anchorage  61  has been formed by cutting and stamping and over which the plastics material block has been molded, avoiding the need to use a bracket. 
     FIG. 20 shows an anchorage for the fastening material block which is formed by two lugs  62  cut and bent out from the flange  100 . 
     In all the foregoing, the plugs are advantageously force-fitted into the ends of the support structure; similar results are obtained simply by inserting the plugs into the ends of the support structure and retaining them there temporarily using retaining means such as screws, pins or other such means, final fastening together of the plug and the structure being achieved by fixing the structure to the frame of the body; of course, in this case, the plugs and support structure are adapted to receive said retaining means.