Abstract:
A vehicle seat includes a backrest and a seat part, at least one of which has a structural element forming a cavity. A filling is disposed in the cavity and configured to influence the stability and/or the deformation behavior of the backrest and/or the seat part. The filling comprises a foam support and a foam material that at least partially surrounds the foam support.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from and the benefit of PCT Application No. PCT/EP2008/004994, filed on Jun. 20, 2008; German Patent No. DE 10 2007 033 776.2, filed on Jul. 18, 2007; German Patent DE 10 2007 033 780.0, filed on Jul. 18, 2007; German Patent No. DE 10 2007 777.0, filed on Jul. 18, 2007; and German Patent No. DE 10 2007 033 783.5, filed on Jul. 18, 2007; all entitled “Structure for a Vehicle Seat”, which are herein incorporated by reference. 
     BACKGROUND 
     The invention relates to a structure for a vehicle seat, which structure comprises rigid structure components which form cavities and comprises a foam structure which at least partially fills the cavities. 
     Such vehicle seats are generally known. For example, the German laid-open specification DE 102 14 476 A1 and the German laid-open specification DE 103 21 289 A1 respectively disclose a frame composed of hollow profiles and a backrest of a vehicle seat, with a foam being arranged in each case in cavities of structural elements. Furthermore, the German laid-open specification DE 10 2004 043 860 A1 and the German laid-open specification DE 197 46 164 A1 respectively disclose a backrest for a seat and a material combination having a profile which is hollow at least in sections, with a foam being arranged in cavities of structural elements. Furthermore, the German laid-open specification DE 42 08 150 A1 and the German laid-open specification DE 197 27 907 A1 respectively disclose a backrest for a vehicle seat and a method for filling cavities in workpieces or semi-finished parts. Furthermore, the German patent document DE 40 28 895 C1 and the European patent application EP 1 591 224 A1 respectively disclose a foam body for partitioning body cavities and a device and method for noise damping in cavities of vehicles. Furthermore, the patent DE 10 2006 014 538 B3 discloses the arrangement of a cable in the interior of a tube on a motor vehicle seat, and an elastic body for a line bushing is known from document DE 198 17279 A1. Furthermore, document DE 36 36 113 A1 discloses a method for forming a foamed mass in a cavity, DE patent 23 03 289 discloses a vehicle seat having a shell which supports a seat back pad, and document DE 37 14 588 A1 discloses a safety seat back beam composed of plastic. 
     It is disadvantageous in the known vehicle seats that, in part, the cavity is always completely filled or else only a partial filling of the cavity is aimed merely at improving the acoustic properties. 
     SUMMARY 
     The object of the present invention is therefore the targeted formation or introduction of a filling in or into a cavity of a structural element of a vehicle seat in order to improve the mechanical properties of the vehicle seat. 
     The object is achieved by means of a vehicle seat having a backrest and having a seat part, with the backrest or the seat part having at least one structural element which has a cavity, with at least one part of the cavity having provided in it a filling which is introduced to influence the stability and/or the deformation behavior of the backrest and/or of the seat part, with the filling having a foam support and a foam material, with the foam material at least partially surrounding the foam support, and with the foam material preferably completely surrounding the foam support. In this way, an improvement in the mechanical properties of the vehicle seat can be obtained in a simple manner in that the filling is arranged and formed such that, during the formation of the foam from the foam material (that is to say during the expansion of the foam material), firstly a good connection, in particular adhesive connection, with the inner surfaces or the inner wall of the structural element is obtained, and such that, secondly, easy insertion of the filling into the cavity is ensured, which leads to ease of assembly of the vehicle seat according to the invention. 
     It is particularly preferable according to the invention for the foam material to be provided so as to expand in an electrocoating kiln. In this way, the foam reinforcement of the vehicle seat can be integrated quickly and in a simple manner in terms of assembly by means of one working step which is carried out in any case. 
     It is particularly preferable if
         the structural element forms, as a cavity, a hollow chamber which runs around in the manner of a frame in the backrest or in the seat part, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber, and/or if   the structural element is formed as a tube in the backrest or in the seat part and forms a hollow chamber which runs around in the manner of a frame, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber, and/or if   the structural element is reinforced by means of the foam material in the region of a belt rolling device, which is provided on the backrest, of an integral belt, in particular in the region of the upper transverse member of the backrest, and/or if   the structural element is reinforced by means of the foam material in the region around a through-loading opening of the backrest, and/or if   the vehicle seat is designed as a belt-integrated seat, with the structural element being reinforced by means of the foam material in the region of a side beam, which has a belt deflecting point or a belt rolling device, of the backrest.
 
In this way, it is possible according to the invention to obtain a targeted reinforcement at highly loaded points of the vehicle seat or of the backrest and/or of the seat part. It is also preferable according to the invention for a combination of a foam reinforcement to take place at more than one of said points. It is hereby advantageously possible according to the invention for the weight and costs of a vehicle seat of said type to be reduced in that, for example, the wall thickness of a metal material to be used, for example steel plate, or else plastic material need not imperatively be designed or selected such that mechanically highly loaded parts or regions of the vehicle seat withstand the occurring loadings, but rather conversely the wall thickness of a material to be used may be reduced and a reinforcement in the form of the filling with, inter alia, the foam material is provided at such mechanically highly loaded parts or regions of the vehicle seat.
       

     A further subject matter of the present invention relates to a vehicle seat having a backrest and a seat part, with the backrest or the seat part having at least one structural element which has a cavity, with at least one part of the cavity having provided in it a filling which is introduced to influence the stability and/or the deformation behavior of the backrest and/or of the seat part and which has a foam material, wherein either
         the structural element forms, as a cavity, a hollow chamber which runs around in the manner of a frame in the backrest or in the seat part, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber,
 
or wherein
   the structural element is formed as a tube in the backrest or in the seat part and forms a hollow chamber which runs around in the manner of a frame, with the hollow chamber having the foam material in its region facing toward a vehicle side region, with the foam material running in particular in a substantially C-shaped manner along the hollow chamber,
 
or wherein
   the structural element is reinforced by means of the foam material in the region of a belt rolling device, which is provided on the backrest, of an integral belt, in particular in the region of the upper transverse member of the backrest,
 
or wherein
   the structural element is reinforced by means of the foam material in the region around a through-loading opening of the backrest,
 
or wherein
   the vehicle seat is designed as a belt-integrated seat, with the structural element being reinforced by means of the foam material in the region of a side beam, which has a belt deflecting point or a belt rolling device, of the backrest. In this way, according to the invention, there are advantageously also alternative possibilities for introducing the filling material into the cavity, for example the injection of plastic material for the formation of foam into the cavity.       

     Further subjects of the present invention relate to
         a method for producing a vehicle seat according to the invention, wherein the structural element which has the cavity is formed in a first step, wherein the still-unexpanded filling, which has the foam support and the foam material, is introduced into the cavity in a second step, and wherein electrocoating is carried out in a third step during which the foam material expands, and to   a method for producing a vehicle seat according to the invention, wherein the still-unexpanded filling, which has the foam support and the foam material, is positioned and/or fastened relative to a part of the structural element in a first step, wherein the cavity is formed in a second step, and wherein electrocoating is carried out in a third step, during which the foam material expands.       

    
    
     
       DRAWINGS 
       The figures schematically illustrate embodiments of the invention by way of example. 
         FIGS. 1 and 2  show a first embodiment of a vehicle seat according to the invention, or of one of its parts. 
         FIG. 3  shows a second embodiment of a vehicle seat according to the invention, or of one of its parts. 
         FIGS. 4 and 5  show a third embodiment of a vehicle seat according to the invention, or of one of its parts. 
         FIGS. 6 and 7  show a fourth embodiment of a vehicle seat according to the invention, or of one of its parts. 
         FIGS. 8 and 9  show a fifth embodiment of a vehicle seat according to the invention, or of one of its parts. 
         FIGS. 10 and 11  show a sixth embodiment of a vehicle seat according to the invention, or of one of its parts. 
         FIGS. 12 and 13  show schematic illustrations of a vehicle seat according to the invention, conforming with all of the embodiments. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 12 and 13  show a vehicle seat according to the invention having features shared by all the embodiments of the present invention. A vehicle seat of said type comprises a seat part  2  and a backrest  3 . Both the seat part  2  and also the backrest  3  have in each case at least one structural element  4  which, below, is also referred to as a seat back segment, seat back structure, longitudinal beam, transverse beam, tube structure, side beam, pressed part or structure component. A cavity  5  is provided at least in partial regions in said structural element  4 , which cavity  5  is also referred to below as a hollow chamber. The cavity  5  is for example in the form of a frame substantially following the outer shape or periphery of the backrest  3  or of the seat part  2 , and is for example substantially round or oval or rounded (for example in the case of tube structures or tube-like structures) or else substantially angular, rectangular, triangular or angled (for example in the case of a U-shaped profile connected to a base plate) in cross section. According to the present invention, at least one partial region of the cavity  5 , and preferably also only one partial region of the cavity  5 , has arranged in it a filling  6  which comprises a foam material  8 . The filling  6  or the foam material  8  is also referred to below as a foam structure. The filling  6  or the foam material  8  may duly be injected from the outside by injecting an easily deformable or foaming material (for example through an opening in the cavity  5 ), but it is preferable according to the present invention for the filling  6  to be introduced into the cavity  5  in the form of a still-unexpanded and substantially hard, or at any rate substantially non-adhesive, foam material  8  which is connected to the foam support  7 , or else fastened to or positioned on a structure part which forms a cavity wall, with the cavity  5  then being formed by means of a connection to another structure part. In a subsequent step, the foam material  8  is then expanded, as a result of which the foam material  8  then at least partially or preferably completely surrounds the foam support  7 . To illustrate this,  FIG. 13  shows a detail of a cavity  5  formed in the structural element  4 , with the filling  6 , that is to say the foam support  7  and the foam material  8 , being illustrated in the cavity  5  in the unexpanded state of the foam material  8  by means of solid lines, and with dashed lines or dots illustrating the limit of the foam material  8  in the foamed state. According to the invention, the expansion of the foam material  8  may take place in particular by means of a KTL bath treatment (not illustrated). This is to be understood to mean a treatment in an electrocoating kiln or a cathodic dip coating process in which the structural elements  4  of the vehicle seat are raised to a temperature of for example approximately 160° to approximately 180° over for example approximately 5 minutes to approximately 15 minutes, preferably approximately 10 minutes. 
       FIG. 1  shows the rear view of a split seat back structure of a first embodiment of a vehicle seat according to the invention, and  FIG. 2  shows a section A-A through the seat back structure according to  FIG. 1 . The seat back structure  11  of the split backrest of a vehicle rear seat bench is composed of a first seat back segment  12  and a second seat back segment  12 ′ which are split for example in the ratio 60:40. Each seat back segment comprises a base plate  13 ,  13 ′ and a pressed part  14 ,  14 ′ which is placed thereon and forms an encircling U-shaped profile. The base plates  13 ,  13 ′ and the pressed parts  14 ,  14 ′ are composed for example of metal, in particular sheet steel or aluminum, or of plastic, for example glass-fiber-reinforced plastic. Here, different materials may also be paired with one another. The seat back segments  12 ,  12 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts  15 ,  15 ′ and a central mount  16 . Rotary latch locks  17 ,  17 ′ arranged laterally on the upper side region of the seat back structure  11  serve to lock the seat back segments  12 ,  12 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The base plates  13 ,  13 ′ and pressed parts  14 ,  14 ′ together form hollow chambers  18 ,  18 ′ which each run around in the manner of a frame. It is provided according to the invention that the outer side beam  19  and the adjoining regions of the upper transverse beam  110  and of the lower transverse beam  111  at least of the relatively large seat back segment  12  are filled with a stiffening foam structure  112 . In the rear view, the filled region in question of the hollow chamber  18  is of approximately C-shaped design ( FIG. 1 ). The introduction of the foam structure  112  may take place by inserting a finished foam part, which is shaped correspondingly to the hollow chamber  18 , before or during the welding of base plate  13  and pressed part  14 . Alternatively, the foam structure  112  is first introduced after the welding process by means of an injection of a foamable mass into the hollow chamber  18 . Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber  18 , which foam precursor is inserted into the hollow chamber  18  before, during or after the welding process and foams to form the foam structure  112  after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure  11 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure  11  is hereby stiffened in the region which is highly loaded in the event of an accident, in such a way that further locking devices—such as for example a so-called shot bolt or a torque lock—can be dispensed with. 
       FIG. 3  shows a second embodiment of the vehicle seat according to the invention. The structure of the rear seat bench  21  comprises separately pivotable seat back segments  22 ,  22 ′ (separated for example into the ratio 60:40) of the backrest  3  and brackets  24 ,  24 ′ which are fastened to the vehicle floor and which have tubular structure components  25 ,  25 ′. The seat back segments  22 ,  22 ′ are rotatably mounted on the respectively associated bracket  24 ,  24 ′. A stiffening foam structure  26  is introduced into the mechanically particularly highly loaded regions A, B and C of the tubular structure components  25 ,  25 ′, that is to say in particular into the longitudinal beams  27 ,  27 ′, which run in the direction of travel, of the bracket  24 ′ of the relatively small seat back segment  22 ′ (regions A, B) and into that part of the transverse beam  29  of the bracket  24  assigned to the relatively large seat back segment  22  which faces toward the central mount  28 . The introduction of the foam structure  26  may for example take place by means of the injection of a foamable mass into the tubular structure components  25 ,  25 ′. Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the interior of the tubular structure components  25 ,  25 ′, which foam precursor foams to form the foam structure  26  after an activation. The activation may take place for example as a result of a supply of heat during the painting of the brackets  24 ,  24 ′. For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. In the second embodiment, the (at least partially) foam-filled structure parts are of tubular design. 
       FIG. 4  shows the rear view of a split seat back structure according to a third embodiment of the vehicle seat according to the invention, and  FIG. 5  shows a section A-A through the seat back structure according to  FIG. 4 . The seat back structure  31  of the split backrest of a vehicle rear seat bench is composed of a first seat back segment  32  and a second seat back segment  32 ′, which are split for example in the ratio 60:40. Each seat back segment  32 ,  32 ′ comprises a base plate  33 ,  33 ′ and a tube structure  34 ,  34 ′ which is placed thereon and which runs around substantially in the manner of a frame. The base plates  33 ,  33 ′ and the tube structures  34 ,  34 ′ are composed for example of metal, in particular of steel or aluminum. Here, different materials may also be paired with one another. The seat back segments  32 ,  32 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts  35 ,  35 ′ and a central mount  36 . Rotary latch locks  37 ,  37 ′ arranged laterally on the upper side region of the seat back structure  31  serve to lock the seat back segments  32 ,  32 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The tube structures  34 ,  34 ′ form substantially encircling hollow chambers  38 ,  38 ′ which are each of frame-like design. It is provided according to the invention that the outer side beam  39  and if appropriate also the adjoining regions of the upper transverse beam  310  and of the lower transverse beam  311  at least of the relatively large seat back segment  32  are filled with a stiffening foam structure  312 . In the rear view, the filled region in question of the hollow chamber  38  is rudimentarily of C-shaped design ( FIG. 4 ). The foam structure  312  may for example be introduced by means of the injection of a foamable mass into the hollow chamber  38 . Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber  38 , which foam precursor foams to form the foam structure  312  after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure  31 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure  31  is hereby stiffened in the region which is highly loaded in the event of an accident, such that further locking devices can be dispensed with. 
       FIG. 6  shows the rear view of a split seat back structure of a fourth embodiment of the vehicle seat, and  FIG. 7  shows a section A-A through the seat back structure according to  FIG. 6 . The seat back structure  41  of the split backrest of a vehicle rear seat bench is composed of a first seat back segment  42  and a second seat back segment  42 ′ which are split for example in the ratio 60:40. Each seat back segment  42 ,  42 ′ comprises a base plate  43 ,  43 ′ and a pressed part  44 ,  44 ′ which is placed thereon and forms an encircling U-shaped profile. The base plates  43 ,  43 ′ and the pressed parts  44 ,  44 ′ are composed for example of metal, in particular sheet steel or aluminum, or of plastic, for example of glass-fiber-reinforced plastic. Here, different materials may also be paired with one another. The seat back segments  42 ,  42 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts  45 ,  45 ′ and a central mount  46 . Rotary latch locks  47 ,  47 ′ arranged laterally on the upper side region of the seat back structure  1  serve to lock the seat back segments  42 ,  42 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The base plates  43 ,  43 ′ and pressed parts  44 ,  44 ′ together form hollow chambers  48  which each run around in the manner of a frame. A belt rolling device  410  of an integral belt is provided in the center of the upper transverse beam  9 . For further stiffening, a vertical beam  411  which is set into the pressed part  44  furthermore runs offset relative to said integral belt in the direction of the central mount  46 . It is provided according to the invention that the upper transverse beam  49  is filled with a stiffening foam structure  412  in the region of the belt rolling device  410 . The introduction of the foam structure  412  may take place by introducing a finished foam part, which is shaped correspondingly to the hollow chamber  8 , before or during the welding of the base plate  43  and pressed part  44 . Alternatively, the foam structure  412  is first introduced after the welding process by means of the injection of a foamable mass into the hollow chamber  48 . Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber  48 , which foam precursor is placed into the hollow chamber  48  before, during or after the welding process and foams to form the foam structure  412  after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure  41 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure  41  is hereby firstly stiffened in the region which is highly loaded in the event of an accident, and secondly the properties of said seat back structure  41  in the event of a head impact are improved. In particular, the deceleration of the test ball during the head impact test is improved. 
       FIG. 8  shows the rear view of a split seat back structure of a fifth embodiment of the vehicle seat according to the invention, and  FIG. 9  shows a section A-A through the seat back structure according to  FIG. 8 . The seat back structure  51  of the split backrest of a vehicle rear seat bench is composed of a first seat back segment  52  and a second seat back segment  52 ′ which are split in the ratio 60:40. Each seat back segment  52 ,  52 ′ comprises a base plate  53 ,  53 ′ and a pressed part  54 ,  54 ′ which is placed thereon and forms an encircling U-shaped profile. The base plates  53 ,  53 ′ and the pressed parts  54 ,  54 ′ are composed for example of metal, in particular sheet steel or aluminum, or of plastic, for example of glass-fiber-reinforced plastic. Here, different materials may also be paired with one another. The seat back segments  52 ,  52 ′ are mounted in the vehicle so as to be rotatable independently of one another by means of side mounts  55 ,  55 ′ and a central mount  56 . Rotary latch locks  57 ,  57 ′ arranged laterally on the upper side region of the seat back structure  51  serve to lock the seat back segments  52 ,  52 ′ to the vehicle body, in particular to the C pillar, in the upright use position. The base plates  53 ,  53 ′ and pressed parts  54 ,  54 ′ together form hollow chambers  58 ,  58 ′ which each run around in the manner of a frame. A through-loading opening  59  is also provided in the relatively large seat back segment  52 , which through-loading opening  59  is surrounded by the upper transverse beam  510 , the lower transverse beam  511 , the central-mount-side vertical beam  512  and a central vertical beam  513  of the pressed part  54 . Here, the central-mount-side vertical beam  512  is of particularly slim design in order to be able to arrange the through-loading opening  59  as centrally as possible in the rear seat bench and to be able to design said through-loading opening  59  to be as large as possible—for example such that said through-loading opening is larger than the transverse extent of a snowboard. It is provided according to the invention that at least the central-mount-side vertical beam  512 , if appropriate also the adjoining regions of the upper transverse beam  510  and of the lower transverse beam  511 , are filled with a stiffening foam structure  514 . The introduction of the foam structure  514  may take place by inserting a finished foam part, which is shaped correspondingly to the hollow chamber  58 , before or during the welding of the base plate  53  and pressed part  54 . Alternatively, the foam structure  514  is first introduced into the hollow chamber  58  after the welding process by means of the injection of a foamable mass. Particularly preferable, however, is the insertion of an in particular strand-like foam precursor, which has a three-dimensional shape, into the hollow chamber  58 , which foam precursor is placed into the hollow chamber  58  before, during or after the welding process and foams to form the foam structure  514  after an activation. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure  51 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. The seat back structure  51  is hereby considerably stiffened in the region  530  which is highly loaded in the event of an accident. 
       FIG. 10  shows the perspective view of a vehicle seat according to the invention as per a sixth embodiment.  FIG. 11  shows a section A-A through the vehicle seat according to  FIG. 10 . The vehicle seat  61  shown in  FIG. 10  has a seat part  62  and a backrest  63  and is designed as a belt-integrated seat in which a belt deflecting point  64  or the belt rolling device is fastened to the upper edge of the backrest  63 . The backrest  63  must therefore dissipate the belt forces into the vehicle floor via the seat back tilt adjuster  65  and the seat part  62 . The side beams  66 ,  66 ′ of the backrest  63  are formed as U-shaped or hollow chamber profiles. In the exemplary embodiment, the side beams  66 ,  66 ′, as shown in  FIG. 11 , are composed of two U-shaped pressed sheet-metal parts  67 ,  68  which are welded to one another at their limb ends in order to form a hollow chamber  69 . At least that side beam  66  which is assigned to the belt deflecting point is provided, in the interior of the hollow chamber  67  over significant regions of its longitudinal extent, with a foam structure  610  which increases the bending stiffness and/or torsional stiffness of the side beam  66 . The sheet-metal parts  67 ,  68  may therefore be formed with a relatively small sheet-metal thickness. The introduction of the foam structure  610  may take place by inserting a finished foam part, which is shaped correspondingly to the hollow chamber  69 , before or during the welding of the sheet-metal parts  67 ,  68 . Alternatively, the foam structure  610  is first introduced into the hollow chamber  69  after the welding process by means of the injection of a foamable mass into the hollow chamber  69 . Particularly preferable, however, is the insertion of an in particular strand-like or sheet-like foam precursor, which has a three-dimensional shape, into the hollow chamber  69 , which foam precursor is placed into the hollow chamber  69  before, during or after the welding process and foams to form the foam structure  610  after an activation. During the foaming of a U-shaped profile, the foaming direction of the foamable mass or of the foam precursor is predefined by suitable sealing means and/or the shape of the foam precursor. The activation may take place for example as a result of a supply of heat during the painting of the seat back structure  61 . For this purpose, use is preferably made of rigidly cross-linking foam systems, for example based on epoxide. 
     It is also preferably provided according to the invention that measures specified in one of the embodiments may also be used in one or more of the other embodiments. It is thus possible according to the invention in particular for a tubular structure part to be provided both in the backrest of the vehicle seat and also in the seat part of the vehicle seat (combination of the second embodiment with the third embodiment). It is also possible for the fourth and/or the fifth embodiment to be combined with one or more of the first, second or third embodiments.