Patent Publication Number: US-2023158989-A1

Title: Vehicle seat back provided with an airbag device and method of assembly such a seat back

Description:
PRIORITY CLAIM 
     This application claims priority to French Patent Application No. FR2112283, filed Nov. 19, 2021, which is expressly incorporated by reference herein. 
     BACKGROUND 
     The present disclosure relates to a vehicle seat back, in particular a motor vehicle seat back. A method for assembling such a seat back as well as a vehicle seat comprising such a seat back are also described. 
     SUMMARY 
     According to the present disclosure, a vehicle seat back comprises a seat back frame with a pillar, an airbag device and a side airbag, the airbag device comprising at least one airbag and an airbag support for attaching the airbag to the seat back frame, and the side airbag comprising a side airbag trim and at least one side airbag trim support for attaching the side airbag to the seat back frame, wherein the trim support and the airbag support comprise at least one assembly point for their attachment to the pillar of the seat back frame. 
     In illustrative embodiments, the assembly point may be common to the trim support and the airbag support for their joint attachment to the pillar of the seat back frame. 
     Thus, advantageously, the assembly formed by the trim support and the airbag support, and therefore more generally by the side airbag, including the trim of the side airbag and the airbag device, is assembled more easily due to the presence of the at least one common assembly point. 
     In illustrative embodiments, the vehicle seat back comprises one or more of the following features, taken alone or in combination: 
     the trim support, at least at the assembly point, is arranged between the pillar of the seat back frame and the airbag support, 
     the trim support and the airbag support are attached to the seat back frame, at the assembly point, by common attachment means, 
     the trim support and the airbag support comprise, for their attachment on the pillar of the seat back frame, two common assembly points: a first point for an upper attachment on the pillar and a second point for a lower attachment on the pillar, the upper attachment being arranged higher than the lower attachment in a vertical direction, 
     the seat back may further comprise a deflector attached to the pillar, the deflector comprising the two assembly points common to the trim support and the airbag support, 
     the side airbag trim comprises a deployment trajectory for airbag deployment 
     the deflector further comprises a border, the border being arranged along the deployment trajectory and diverging from the deployment trajectory for the deployment of the airbag between the border and the deployment trajectory, 
     the trim support comprises a guide wall configured to direct the deployment of the airbag toward the deployment trajectory, 
     the trim support and the airbag support comprise different materials, the trim support preferably being made of plastic material and the airbag support being made of metallic materials. 
     In illustrative embodiments, a method of assembling a vehicle seat back comprising a seat back frame, an airbag device comprising at least one airbag and an airbag support for attaching the airbag, and a side airbag comprising a side airbag trim and at least one side airbag trim support ( 40 ) for its attachment to the seat back frame, the method comprising: 
     preassembling the airbag support of the airbag device with the trim support of the side airbag, 
     attaching the assembly formed, on the one hand, by the side airbag comprising the side airbag trim and the trim support, and on the other hand the airbag device on the seat back frame, by at least one assembly point for attaching the trim support and the airbag support to the seat back frame pillar. 
     Furthermore, the assembly point may be common to the trim support and the airbag support, and the method may comprise: 
     preassembling the airbag support of the airbag device with the trim support of the side airbag, comprises matching the common assembly point between the trim support and the airbag support. 
     Additionally, the seat back may comprise a deflector, the method further comprising: 
     preassembling the deflector on the assembly formed, on the one hand, by the side airbag comprising the side airbag trim and the trim support and, on the other hand, the airbag device, 
     attaching the assembly formed by the side airbag, the airbag device and the deflector on the seat back frame by the at least one common assembly point of the trim support and the airbag support for their attachment on the pillar of the seat back frame. 
     In illustrative embodiments, also disclosed is a motor vehicle seat comprising a seat bottom with a seat bottom frame and a seat back as described above. 
     Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       The detailed description particularly refers to the accompanying figures in which: 
         FIG.  1    schematically shows a side view of an example of a vehicle seat; 
         FIG.  2    schematically shows a side view of an example of a side part of a vehicle seat; 
         FIG.  3    schematically shows, in perspective view, an example of a seat back frame equipped with an example of a side airbag device, which can be implemented in the vehicle seat of  FIG.  1   ; and 
         FIG.  4    schematically shows a sectional view along the axis A-A of the vehicle seat example of  FIG.  2   . 
     
    
    
     DETAILED DESCRIPTION 
     In the various figures, the same references designate identical or similar elements. For the sake of conciseness, only the elements that are useful for understanding the described embodiment are shown in the figures and are described in detail below. 
     In the following description, when referring to absolute position qualifiers, such as “front,” “rear,” “top,” “bottom,” “left,” “right,” etc., or relative position qualifiers, such as “above,” “below,” “upper,” “lower,” etc., or to qualifiers of orientation, such as “horizontal,” “vertical,” etc., reference is made, unless otherwise specified, to the orientation of the figures or of a vehicle seat in its normal usage position. 
     In particular, the longitudinal direction X means the longitudinal direction of the seat. The longitudinal direction of the seat is considered to be the same as the longitudinal direction of the motor vehicle in which the seat is mounted. This longitudinal direction X corresponds to the normal direction of advance of the vehicle. The longitudinal direction X is horizontal. The transverse direction Y of the seat thus corresponds to the transverse or lateral direction of the motor vehicle. This transverse direction corresponds to a direction perpendicular to the normal direction of advance of the vehicle. The transverse direction Y is horizontal. Finally, the vertical direction Z is a vertical direction of the seat, perpendicular to the longitudinal and transverse directions. 
       FIG.  1    schematically shows a motor vehicle seat  10  mounted on a slide mechanism  12 . 
     The seat  10  comprises a seat bottom  13 , with a seat bottom frame  14  and a seat bottom trim  15 , on which a seat back  16 , with a seat back frame  17  and a seat back trim  18 , is mounted. The seat back frame  17  here is pivoting about a transverse axis A, with respect to the seat bottom frame  14 . To do this, a hinge mechanism  20  is arranged between the seat bottom frame  14  and the seat back frame  17 . 
     The seat back trim  18  may further comprise a central airbag that comprises a central trim (not shown), and of two side airbags that respectively comprise two side airbag trims  19 , and Each side airbag is arranged on the seat back frame  17 , laterally, on either side of the central airbag. The trim (of the central airbag or the side airbags) typically forms a padding, for example an expanded foam, conferring the softness and the comfort of the seat 
     The seat bottom  13  is mounted on movable sections  22 , also called slides or male sections, via feet  24 ,  26 . Each movable section  22  is part of a slide  12  and is associated with a fixed section  28 . The fixed section  28  is also called “rail” or “female section.” The fixed section  28  is attached to the floor  30  of a motor vehicle. 
     According to the illustrated example, the seat  10  can also comprise a headrest  34 . The headrest  34  may also comprise a headrest frame and headrest trim. 
     In the following, we provide more detailed descriptions of examples of seat backs  16  that can be implemented in the seat  10  of [ FIG.  1   ], with reference to  FIGS.  2  to  4   . 
     As illustrated in [ FIG.  2   ], the seat back frame  17  comprises a first pillar  17   a , a second pillar  17   b , a first crosspiece  17   c , hereinafter called “lower crosspiece  17   c ,” and a second crosspiece  17   d , hereinafter called “upper crosspiece  17   d .” The pillars  17   a ,  17   b  and the crosspieces  17   c ,  17   d  form a seat back frame  17  in the form of a housing. To do this, the pillars  17   a ,  17   b  and the crosspieces  17   c ,  17   d  can be attached together, in particular welded together. Alternatively, the seat back frame  17  is in one piece, the latter for example being molded. 
     The first pillar  17   a  is intended to be arranged as centrally as possible in the motor vehicle, while the second pillar  17   b  is intended to be arranged closest to a lateral side of the vehicle. The lower crosspiece  17   c  is intended to be the closest crosspiece to the hinge device  20 , the hinge device even being able to be attached on the lower crosspiece  17   c . The upper crosspiece  17   d  is intended to be the closest crosspiece to the headrest  34 . 
     In the remainder of the description, the present disclosure is arbitrarily described with reference to the first pillar  17   a . However, the present disclosure may alternatively or additionally be implemented on the second pillar  17   b.    
     As illustrated in this [ FIG.  2   ], the first pillar  17   a  comprises an upper attachment  26  and a lower attachment  27 . The upper and lower attachments  26 ,  27  are through holes provided to receive attachment means  60 , as described below. In the vertical direction Z, the upper attachment  26  is provided in the upper part of the first pillar  17   a  and the lower attachment  27  is provided in the lower part of the first pillar  17   a , the upper attachment  26  being positioned higher than the lower attachment  27 , relative to the vertical direction Z. 
     As illustrated in [ FIG.  2   ] and in more detail in [ FIG.  3   ], a side airbag is arranged on the first pillar  17   a . In [ FIG.  2   ], it can be seen that the side airbag trim  19  comprises, in the longitudinal direction X, an outer edge  19   a  and an inner edge  19   b . The inner edge  19   b  is designed to be arranged in contact with, or in the immediate vicinity of, a rear part of a vehicle seat, such as for example a vehicle seat rear shell. The inner edge  19   b  is preferably a trim section that is attached to the trim support  40 , in particular on which the seat back foam is overmolded. The inner edge  19   b  is also preferably arranged in line with the first pillar  17   a.    
     In addition, advantageously, the inner edge  19   b  of the side airbag trim  19  can constitute a deployment trajectory for a side airbag device  36  (detailed below). Alternatively, the deployment trajectory (inner edge  19   b ) can be completed by a guide wall or inclined wall  19   c . The guide wall  19   c , visible in the sectional view of [ FIG.  4   ] along the axis A-A illustrated in [ FIG.  2   ], directs the deployment of an airbag of the side airbag device  36  toward the deployment trajectory. This wall  19   c  is produced by a trim section of the seat back side airbag, which preferably belongs to a trim support  40 . The wall  19   c  thus separates the airbag zone from the rear face of the foam and the seat back side airbag trim and thus provides deployment of the airbag toward the deployment trajectory, without tearing the foam. 
     Furthermore, in addition to the side airbag trim  19 , the side airbag comprises a trim support  40  for attaching the side airbag trim  19  on the first pillar  17   a.    
       FIG.  3    shows the trim support  40  without the side airbag trim  19 . The trim support is preferably made of plastic material. The trim support  40  is attached to the first pillar  17   a  via two assembly points  41 ,  42 . More specifically, the trim support  40  is attached to the first pillar  17   a  via a first point  41  and a second point  42 . The first point  41  is provided to cooperate with the upper attachment  26  arranged on the first pillar  17   a , and the second point  42  is provided to cooperate with the lower attachment  27  arranged on the first pillar  17   a . The first and second points  41 ,  42  cooperate with the upper  26  and lower  27  attachments, respectively, via the attachment means  60 . The attachment means  60  are for example bolt-nut assemblies or rivets. The attachment means  60  thus allow the solid attachment of the trim support  40  (and therefore of the side airbag trim  19 ) on the first pillar  17   a.    
     Therefore, according to the present disclosure, the attachment of the side airbag trim  19  to a pillar of the frame  17  uses only two attachment points. 
       FIG.  3    further illustrates a side airbag device  36 , arranged on the first pillar  17   a . Alternatively, the side airbag device  36  can be arranged on the second pillar  17   b.    
     Here, the side airbag device  36  comprises an airbag  44  and an airbag  44  inflation cartridge  46 . The airbag  44  and the cartridge  46  are arranged in a pouch  38 , or sleeve. The pouch  38  is made of non-woven textile material. The cartridge  46  is in fluid communication with the airbag  44 . The pouch  38  is shaped to open in the event the airbag  44  is deployed. 
     The side airbag device  36  further comprises an airbag support  50 , to be arranged on the first pillar  17   a . The cartridge  46  is for example attached to the airbag support  50 , on a plate  51 . 
     The airbag support  50  extends longitudinally in the vertical direction Z, between an upper end of the airbag support  53  and a lower end of the airbag support  52 . The airbag support is preferably made of metallic material, such as for example steel. The airbag support  50  is attached to the first pillar  17   a  via the two assembly points  41 ,  42 , also provided for attaching the trim support  40  to the first pillar  17   a . The first point  41  may be provided toward the upper airbag support end  53  and the second point  42  may be provided toward the lower airbag support end  52 . The trim support  40  and the airbag support  50  thus comprise two common assembly points for their common attachment to the first pillar  17   a . In other words, the airbag support  50  and the trim support  40  are both attached together on the pillar, by common assembly points. 
     Furthermore, the airbag support  50  is arranged on the trim support  40 . It is therefore understood that, once the airbag support  50  and the trim support  40  are attached on the pillar, the trim support  40  is arranged between the airbag support  50  and the pillar. In other words, the airbag support  50  is arranged on the trim support  40 , which in turn is arranged on the pillar. The airbag support  50  is therefore superimposed on the trim support  40 , which is superimposed on the pillar. 
     Alternatively, the side airbag device  36  may comprise an intermediate plate (not shown) on which the plate  51  supporting the cartridge  46  is attached. The intermediate plate can for example be made of metal, such as steel for example. The intermediate plate is attached to the airbag support  50 . Described another way, the cartridge  46  is attached to the first pillar  17   a  via the intermediate plate, which in turn is attached to the airbag support  50 . Provision can also be made for the intermediate plate to have at least one assembly point  41  and/or  42  common to the airbag support  50 . f 
     It can thus be noted that the assembly of the trim support  40  and the airbag support  50  on a pillar is particularly easy, since the assembly uses only two assembly points, these points being common, i.e. identical, to the trim support  40  and the airbag support  50 . In other words, only the two assembly points  41 ,  42  allow the trim support  40  and the airbag support  50  to be attached to a pillar of the frame  17 . 
     Alternatively, a deflector  70  can be attached to the first pillar  17   a . In this case, as visible in  FIG.  2   , the deflector  70  is arranged above the side airbag device  36 . In other words, the deflector  70  envelops the side airbag device  36 . 
     The deflector  70  extends longitudinally in the vertical direction Z, between an upper end of the deflector  73  and a lower end of the deflector  72 . The deflector  70  is attached to the first pillar  17   a  via the two assembly points  41 ,  42 , also provided for attaching the trim support  40  and the airbag support  50  to the first pillar  17   a . The first point  41  may be provided toward the upper deflector support end  73  and the second point  42  may be provided toward the lower deflector support end  72 . The trim support  40 , the airbag support  50  and the deflector  70  thus comprise two common assembly points for their common attachment to the first pillar  17   a.    
     The deflector  70  is configured to direct the deployment of the airbag  44 . A border  71 , or trim section, is arranged on the deflector  70 . The border  71  is further arranged along the inner edge  19   c  of the side airbag  19 . The border  71  can be of complementary shape to the inner edge  19   b , and thus follow the shape of the side airbag trim  19 . The airbag  44  deploys along the border  71 . Preferably, the deflector  70  may be a one-layer polyurethane coating. The deflector  70  comprises a semi-rigid material, such as polyurethane for example. In the event the airbag  44  is deployed, the border  71 , due to the flexibility of the deflector  70 , moves away from the deployment trajectory of the side airbag trim  19  to allow the airbag  44  to deploy. 
     We will now describe a method of assembling the seat back  16  of the vehicle seat. The method is described here with reference to the first pillar  17   a , but can also be implemented on the second pillar  17   b.    
     In general, the method comprises attaching the side airbag to the first pillar  17   a , including the side airbag trim  19  and the trim support  40  on which the side airbag device  36  is pre-mounted (or pre-assembled). The assembly including the side airbag and the side airbag device  36  is thus attached to the first pillar  17   a  in a single assembly step. The mounting of the side airbag device  36  can therefore be done simultaneously with the attachment of the side airbag (including the trim of the side airbag  19  and the trim support  40 ) on the first pillar  17   a . This results in a simplification and time saving of the assembly method of the seat back. 
     More specifically, the method comprises: 
     preassembling the side airbag device  36  with the trim support  40 . In particular, the side airbag device  36  is placed on the trim support  40  so that the assembly points coincide, that is to say, a single first assembly point  41  and a single second assembly point  42 . 
     Then, the method comprises: 
     attaching the assembly formed on the one hand by the side airbag, including the trim support  40  and the side airbag trim  19 , and on the other hand, the side airbag device  36  on the seat back frame  17 . In particular, the first assembly point  41  and the second assembly point  42  of the assembly formed by the trim support  40  and the side airbag device  36  are made to correspond with the upper attachment  26  and the lower attachment  27 , respectively, of the first pillar  17   a . The assembly formed by the trim support  40  and the side airbag device  36  is then attached on the seat back frame  17 , using the attachment means  60 , provided to cooperate with the first and second assembly points  41 ,  42 , at the upper attachment  26  and the lower attachment  27 . 
     Additionally, the method may comprise: 
     preassembling the deflector  70  on the assembly formed by the trim support  40  and the side airbag device  36 . The deflector  70  is in this case mounted on the trim support  40 , above the side airbag device  36 . This results in a single first assembly point  41  and a single second assembly point  42 . The assembly formed by the trim support  40 , the side airbag device  36  and the deflector  70  is then attached as outlined in the previous paragraph. 
     The method described, according to the present disclosure, therefore makes it possible to prepare, on the one hand, the elements to be attached on a pillar of the seat back frame  17  before, on the other hand, attaching them on the pillar. It is thus not necessary to provide the pillar from the start of the seat back assembly method; the preparatory steps can be prepared at a distance from the frame before attaching, in one piece, the side trim and airbag elements on the pillar of the frame. 
     A comparative seat back may be provided with a side airbag device. Such a device may be attached to a pillar of the seat back frame. Such a side airbag device may aim to limit the risk of the seat&#39;s occupant colliding with the door, or even the central pillar of the passenger compartment of the vehicle, or else may aim to limit the risk of head-to-head impacts of the occupants of two seats arranged transversely one beside the other in the motor vehicle when located on the centermost pillar of the vehicle when located on the other pillar, on the inside. 
     However, the manufacture of such a comparative seat, in particular comprising positioning the device inside a cover before attaching it to the frame, complicates the assembly of the airbag device. Under these conditions, the side airbag device may be attached in a dedicated mounting step on the pillar of the seat back frame. 
     It appeared that because of this dedicated mounting step, the assembly of the various elements that constitute the seat back is particularly complex and time-consuming. 
     In addition, such an airbag device determines the profile of the seat, which makes it necessary to design the seat according to the size of the airbag device. 
     The present disclosure improves the situation. 
     Vehicle ( 10 ) seat back ( 16 ) comprising a seat back frame ( 17 ) with a pillar ( 17   a ,  17   b ), an airbag device ( 36 ) and a side airbag, the airbag device ( 36 ) comprising at least one airbag ( 44 ) and an airbag support ( 50 ) for attaching the airbag ( 44 ) to the seat back frame ( 17 ), and the side airbag comprising a side airbag trim ( 19 ) and at least one side airbag trim support ( 40 ) for attaching the side airbag to the seat back frame ( 17 ), wherein the trim support ( 40 ) and the airbag support ( 50 ) comprise at least one assembly point ( 41 ,  42 ) for their attachment to the pillar ( 17   a ,  17   b ) of the seat back frame ( 17 ).