Patent Publication Number: US-2022219760-A1

Title: Motor vehicle structure with reinforcing part between the roof crossmember and the roof arch beam

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the US National Stage under 35 USC § 371 of International Application No. PCT/FR2020/050970, filed 8 Jun. 2020 which claims the priority of the French application 1906606 filed on 19 Jun. 2029, the content (text, drawings and claims) of both said applications being incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates to the field of motor vehicles and, more particularly, to the structure of a motor vehicle. 
     BACKGROUND 
     A number of organizations implement test protocols, on behalf of governments, on vehicles, to test the reliability of said vehicles, or indeed theft resistance in the event of an impact. Thus, a “lateral post impact” protocol tests the resistance of the vehicle and the damage suffered by the passengers, in the event of a lateral impact in the region of the lateral central upright or center pillar of the vehicle. 
     The motor vehicle structure comprises, in a conventional manner, two roof arch beams positioned on either side of a roof. A roof crossmember is positioned below the roof and is fastened laterally to the two roof arch beams. Moreover, a reinforcing part can be used at each of the ends of the crossmember in order to reinforce the connection to the corresponding roof arch beam. However, hi the event of a lateral post impact, the end of the roof crossmember can separate from the corresponding roof arch beam, thus causing injury to the passengers. 
     FR 2 932 150 A1 discloses a roof crossmember comprising grooves, the crossmember being attached, at each of the ends thereof, to a roof arch beam. 
     However, the connection between the end of the roof crossmember and the corresponding roof arch beam is fragile. 
     Indeed, this connection carries a significant risk of rupture in the case of a lateral post impact. 
     EP 1 449 746 A2 discloses the connection between a lateral central upright, a roof crossmember, and the roof of the motor vehicle. A reinforcing part is positioned between the two panels forming the central lateral upright, and is fastened to the roof crossmember and to the roof. However, this connection may be deficient, in particular in the event of a lateral post impact. 
     SUMMARY 
     The invention aims to overcome at least one of the disadvantages of the prior art mentioned above. More particularly, the invention aims to improve the strength of the connection between the roof crossmember and the roof arch beam, in particular in the case of a lateral post impact. 
     Briefly, a motor vehicle structure is disclosed, the motor vehicle structure comprising: two roof arch beams arranged laterally on either side of the motor vehicle structure, a roof crossmember comprising two ends which are fastened to the two roof arch beams, respectively, and a reinforcing part for the fastening of each of the ends of the crossmember to the corresponding roof arch beam. Notably, each of the ends of the roof crossmember is arranged between the corresponding reinforcing part and the roof arch beam. 
     According to an advantageous embodiment, each of the reinforcing parts is a swaged part extending according to a main longitudinal direction of the vehicle, on either side of the corresponding end of the two ends of the roof crossmember. 
     According to an advantageous embodiment, the two ends of the roof crossmember comprise grooves, each of the reinforcing parts comprising a central portion which fits the grooves of the corresponding end, and two distal portions fastened directly to the corresponding roof arch beam. 
     According to an advantageous embodiment, the distal portions of each of the reinforcing parts are fastened by one or more electric resistance welding points to the roof arch beam. 
     According to an advantageous embodiment, the central portion of each of the reinforcing parts is fastened to the corresponding end of the two ends of the roof crossmember by one or more electric resistance welding points. 
     According to an advantageous embodiment, each of the two ends of the roof crossmember is fastened to the corresponding beam of the two roof arch beams by one or more electric resistance welding points. 
     According to an advantageous embodiment, each of the reinforcing parts is of a generally rectangular or trapezoidal shape. 
     According to an advantageous embodiment, each of the reinforcing parts extends laterally beyond the roof arch beam, towards the interior of the vehicle. 
     According to an advantageous embodiment, the additional extension is at least 15 mm. 
     According to an advantageous embodiment, the roof crossmember is located longitudinally in the region of two lateral central uprights. 
     The disclosed structure of the motor vehicle improves the connection between the roof arch beam and the roof crossmember. This improvement is due to the presence of a reinforcing part positioned above each end of the roof crossmember, the reinforcing part being fastened to the corresponding underlying roof arch beam. The positioning of the reinforcing part above each end of the crossmember makes it possible to maintain the connection during the two phases of a lateral post impact: the shearing phase and the traction phase. Moreover, the reinforcing part is simple in design and manufacture, and can be implemented by means of techniques and materials known to a person skilled in the art. The fastening thereof to the structure of the vehicle is also simple to implement, and widely carried out in the motor industry. 
     Other features and advantages of the structure of the motor vehicle will become clear from the description and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a motor vehicle structure; 
         FIG. 2  is an exploded view of the connection between a roof arch beam, a roof crossmember, and a reinforcing part; 
         FIG. 3  is a view from below of the connection shown in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the connection of  FIGS. 2 and 3 , at a first stage of performance of a lateral post impact: the shearing phase; and 
         FIG. 5  is a cross-sectional view of the connection of  FIGS. 2 and 3 , at a second stage of performance of a lateral post impact: the traction phase. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a view of a motor vehicle structure. 
     The vehicle structure  1  comprises a roof (not shown, for reasons of clarity) and two lateral sides  3  located on either side of said roof. A roof arch beam  5  is located at each of the lateral sides  3 , and laterally at the roof. Said beam  5  extends from a lateral front upright  7 , or front foot of the vehicle, towards the rear of the vehicle. Moreover, at each of the sides  3  of the vehicle, a lateral central upright  11 , or center pillar, of the vehicle extends from a base  9  towards a mid-portion (shown in  FIGS. 2 and 3 ) and the corresponding roof arch beam  5 . A roof crossmember  13  also extends between the two roof arch beams  5  in the region of the lateral central uprights  11 . This crossmember  13  comprises two ends (visible in  FIGS. 2 and 5 ), each end of the crossmember  13  being arranged between a reinforcing part  15  and the corresponding roof arch beam  5 , each end being fastened to the corresponding beam  5 . The reinforcing part  15  serves to fasten each of the ends of the crossmember  13  to the corresponding roof arch beam  5 . 
       FIGS. 2 and 3  are two views of the connection between the corresponding roof crossmember, the roof arch beam, and the reinforcing part. These figures show the connection of the left-hand side of the vehicle, but can also apply to a connection located on the right-hand side of the vehicle. 
     In these figures, the lateral central upright  11  comprises a vertical portion  11 A extending at the height of the structure of the vehicle, and a flared upper end  11 B at the junction with the roof arch beam  5 . The vertical portion  11 A of the lateral central upright  11  has a U-shaped cross section which is capable of improving the absorption of impacts, in particular the absorption of a lateral post impact. 
     The roof arch beam  5  extends longitudinally along the roof (not visible in these drawings). The roof arch beam  5  has a U-shaped cross section which is capable of improving the absorption of impacts. The mid portion  5 A of each beam  5  comprises a reinforcement  5 B which is capable of receiving the corresponding end  13 A of the roof crossmember  13 . A receiving zone  5 D for receiving the upper end  11 B of the corresponding lateral central upright  11  is located on an outside face  50  of the mid portion  5 A of the beam  5 . Thus, the roof crossmember  13  is located longitudinally in the region of two lateral central uprights  11 . 
     The end  13 A of the roof crossmember  13  comprises, in  FIGS. 2 and 3 , grooves  13 B. Moreover, this end  13 A is accommodated in the reinforcement  5 B of the roof arch beam  5 , and is fastened there by one or more electric resistance welding points  150 . A mid portion  130  of the crossmember  13  is cantilevered between the two grooves  13 B. 
     Finally, the connection comprises the reinforcing part  15 . Said reinforcing part  15  is a swaged part which is generally rectangular or trapezoidal in shape and which extends according to a main longitudinal direction, on either side of the end  13 A of the roof crossmember  13 . The reinforcing part  15  comprises a central portion  15 A which fits the grooves  13 B of the end  13 A of the crossmember  13 . Said central portion  15 A is fastened to the end  13 A of the crossmember  13  by one or more electric resistance welding points  150 . The reinforcing part  15  furthermore comprises two distal portions  15 B which are fastened directly to the roof arch beam  5  by one or more electric resistance welding points  15 D. Moreover, the reinforcing part  15  extends laterally beyond the roof arch beam  5 , towards the interior of the vehicle, said additional extension being at least 15 mm. 
       FIGS. 4 and 5  show the connection between an end of the corresponding roof crossmember, the corresponding lateral central upright, and the corresponding roof arch beam, during a lateral post impact. 
     In a first step ( FIG. 4 ), the connection works in shear. The connection between the roof crossmember  13  and the roof arch beam  5  is maintained by the presence of the reinforcing part  15  which, being positioned on the end  13 A of the crossmember  13 , keeps the end  13 A of the crossmember  13  on the underlying roof arch beam  5  and thus ensures the hold of the connection. 
     In a second step ( FIG. 5 ), the connection works in traction, following the folding of the roof crossmember  13 . This traction phase must occur as late as possible, so as to optimize the function of the crossmember  13 . During this phase, the crossmember  13  bears against the reinforcing part  15 . The stress is thus distributed over the entire width of the reinforcing part  15 , which makes it possible for the connection to be maintained during the second phase of the impact. 
     TECHNICAL FIELD 
     The present invention claims the priority of the French application 1906606 filed on 19 Jun. 2019, the content of which (text, drawings and claims) is incorporated herein by reference. 
     The invention relates to the field of motor vehicles and, more particularly, to the structure of a motor vehicle. 
     PRIOR ART 
     A number of organizations implement test protocols, on behalf of governments, on vehicles, which protocols serve in particular to test the reliability of said vehicles, or indeed their resistance in the event of an impact. Thus, a “lateral post impact” protocol makes it possible to test the resistance of the vehicle and the damage suffered by the passengers, in the event of a lateral impact in the region of the lateral central upright or center pillar of the vehicle. 
     The motor vehicle structure comprises, in a conventional manner, two roof arch beams positioned on either side of a roof. A roof crossmember is positioned below the roof and is fastened laterally to the two roof arch beams. Moreover, a reinforcing part can be used at each of the ends of the crossmember in order to reinforce the connection to the corresponding roof arch beam. However, in the event of a lateral post impact, the end of the roof crossmember can separate from the corresponding roof arch beam, thus causing injury to the passengers. 
     The published patent document FR 2 932 150 A1 discloses a roof crossmember comprising grooves, the crossmember being attached, at each of the ends thereof, to a roof arch beam. However, the connection between the end of the roof crossmember and the corresponding roof arch beam is fragile. 
     Indeed, this connection carries a significant risk of rupture in the case of a lateral post impact. 
     The published patent document ER 1 449 746 A2 discloses the connection between a lateral central upright, a roof crossmember, and the roof of the motor vehicle. A reinforcing part is positioned between the two panels forming the central lateral upright, and is fastened to the roof crossmember and to the roof. However, this connection may be deficient, in particular in the event of a lateral post impact. 
     DISCLOSURE OF THE INVENTION 
     The invention aims to overcome at least one of the disadvantages of the prior art mentioned above. More particularly, the invention aims to improve the strength of the connection between the roof crossmember and the roof arch beam, in particular in the case of a lateral post impact. 
     The invention relates to a motor vehicle structure, comprising: two roof arch beams arranged laterally on either side of the motor vehicle structure, a roof crossmember comprising two ends which are fastened to the two roof arch beams, respectively, and a reinforcing part for the fastening of each of the ends of the crossmember to the corresponding roof arch beam, notable in that each of the ends of the roof crossmember is arranged between the corresponding reinforcing part and the roof arch beam. 
     According to an advantageous embodiment of the invention, each of the reinforcing parts is a swaged part extending according to a main longitudinal direction, on either side of the corresponding end of the two ends of the roof crossmember. 
     According to an advantageous embodiment of the invention, the two ends of the roof crossmember comprise grooves, each of the reinforcing parts comprising a central portion which fits the grooves of the corresponding end, and two distal portions fastened directly to the corresponding roof arch beam. 
     According to an advantageous embodiment of the invention, the distal portions of each of the reinforcing parts are fastened by one or more electric resistance welding points to the roof arch beam. 
     According to an advantageous embodiment of the invention, the central portion of each of the reinforcing parts is fastened to the corresponding end of the two ends of the roof crossmember by one or more electric resistance welding points. 
     According to an advantageous embodiment of the invention, each of the two ends of the roof crossmember is fastened to the corresponding beam of the two root arch beams by one or more electric resistance welding points. 
     According to an advantageous embodiment of the invention, each of the reinforcing parts is of a generally rectangular or trapezoidal shape. 
     According to an advantageous embodiment of the invention, each of the reinforcing parts extends laterally beyond the roof arch beam, towards the interior of the vehicle. 
     According to an advantageous embodiment of the invention, the additional extension is at least 15 mm. 
     According to an advantageous embodiment of the invention, the roof crossmember is located longitudinally in the region of two lateral central uprights. 
     The measures of the invention are of interest in that they make it possible to improve the connection between the roof arch beam and the roof crossmember. This improvement is due to the presence of a reinforcing part positioned above each end of the roof crossmember, the part being fastened to the corresponding underlying roof arch beam. The positioning of the reinforcing part above each end of the crossmember makes it possible to maintain the connection during the two phases of a lateral post impact: the shearing phase and the traction phase. Moreover, the reinforcing part is simple in design and manufacture, implemented by means of techniques and materials known to a person skilled in the art. The fastening thereof to the structure of the vehicle is also simple to implement, and widely carried out in the motor industry. 
     Other features and advantages of the present invention will become clear from the description and the drawings. 
     BRIEF DESCRIPTION OAF THE DRAWINGS 
       FIG. 1  is a perspective view of a motor vehicle structure; 
       FIG. 2  is an exploded view of the connection between a roof arch beam, a roof crossmember, and a reinforcing part; 
       FIG. 3  is a view from below of the connection shown in  FIG. 2 ; 
       FIG. 4  is a cross-sectional view of the connection of  FIGS. 2 and 3 , at a first stage of performance of a lateral post impact: the shearing phase; 
       FIG. 5  is a cross-sectional view of the connection of  FIGS. 2 and 3 , at a second stage of performance of a lateral post impact: the traction phase. 
     DETAILED DESCRIPTION 
       FIG. 1  is a view of a motor vehicle structure according to the invention. 
     The vehicle structure  1  comprises a roof (not shown, for reasons of clarity) and two lateral sides  3  located on either side of said roof. A roof arch beam  5  is located at each of the lateral sides  3 , and laterally at the roof. Said beam  5  extends from a lateral front upright  7 , or front foot of the vehicle, towards the rear of the vehicle. Moreover, at each of the sides  3  of the vehicle, a lateral central upright  11 , or center pillar, of the vehicle extends from a base  9  towards a mid-portion (shown in  FIGS. 2 and 3 ) and the corresponding roof arch beam  5 . A roof crossmember  13  also extends between the two roof arch beams  5  in the region of the lateral central uprights  11 . This crossmember  13  comprises two ends (visible in  FIGS. 2 and 5 ), each end of the crossmember  13  being arranged between a reinforcing part  15  and the corresponding roof arch beam  5 , each end being fastened to the corresponding beam  5 . The reinforcing part  15  serves to fasten each of the ends of the crossmember  13  to the corresponding roof arch beam  5 . 
       FIGS. 2 and 3  are two views of the connection between the corresponding roof crossmember, the roof arch beam, and the reinforcing part. These figures show the connection of the left-hand side of the vehicle, but can also apply to a connection located on the right-hand side of the vehicle. 
     In these figures, the lateral central upright  11  comprises a vertical portion  11 A extending at the height of the structure of the vehicle, and a flared upper end  11 B at the junction with the roof arch beam  5 . The vertical portion  11 A of the lateral central upright  11  has a U-shaped cross section which is capable of improving the absorption of impacts, in particular the absorption of a lateral post impact. 
     The roof arch beam  5  extends longitudinally along the roof (not visible in these drawings). The roof arch beam  5  has a U-shaped cross section which is capable of improving the absorption of impacts. The mid portion  5 A of each beam  5  comprises a reinforcement  5 B which is capable of receiving the corresponding end  13 A of the roof crossmember  13 . A receiving zone  5 D for receiving the upper end  11 B of the corresponding lateral central upright  11  is located on an outside face  5 C of the mid portion  5 A of the beam  5 . Thus, the roof crossmember  13  is located longitudinally in the region of two lateral central uprights  11 . 
     The end  13 A of the roof crossmember  13  comprises, in  FIGS. 2 and 3 , grooves  13 B. Moreover, this end  13 A is accommodated in the reinforcement  5 B of the roof arch beam  5 , and is fastened there by one or more electric resistance welding points  150 . A mid portion  130  of the crossmember  13  is cantilevered between the two grooves  13 B. 
     Finally, the connection comprises the reinforcing part  15 . Said reinforcing part  15  is a swaged part which is generally rectangular or trapezoidal in shape and which extends according to a main longitudinal direction, on either side of the end  13 A of the roof crossmember  13 . The reinforcing part  15  comprises a central portion  15 A which fits the grooves  13 B of the end  13 A of the crossmember  13 . Said central portion  15 A is fastened to the end  13 A of the crossmember  13  by one or more electric resistance welding points  150 . The reinforcing part  15  furthermore comprises two distal portions  15 B which are fastened directly to the roof arch beam  5  by one or more electric resistance welding points  15 D. Moreover, the reinforcing part  15  extends laterally beyond the roof arch beam  5 , towards the interior of the vehicle, said additional extension being at least 15 mm. 
       FIGS. 4 and 5  show the connection between an end of the corresponding roof crossmember, the corresponding lateral central upright, and the corresponding roof arch beam, during a lateral post impact. 
     In a first step ( FIG. 4 ), the connection works in shear. The connection between the roof crossmember  13  and the roof arch beam  5  is maintained by the presence of the reinforcing part  15  which, being positioned on the end  13 A of the crossmember  13 , keeps this on the underlying roof arch beam  5  and thus ensures the hold of the connection. 
     In a second step ( FIG. 5 ), the connection works in traction, following the folding of the roof crossmember  13 . This traction phase must occur as late as possible, so as to optimize the function of the crossmember  13 . During this phase, the crossmember  13  bears against the reinforcing part  15 . The stress is thus distributed over the entire width of the reinforcing part  15 , which makes it possible for the connection to be maintained during the second phase of the impact.