Structural assembly for a vehicle seat backrest

Abstract

Structural assembly (1) for a vehicle seat backrest, comprising: - a surface element (10) designed and configured to form at least a part of a rear wall of the vehicle seat backrest and / or to close a recess for a pass-through in the vehicle seat backrest, and - at least one interface element (12A-12R) designed and configured for connection with a further component (2-5) of the vehicle seat backrest, characterized in that the surface element (10) is made of a thermoformable composite material and is materially bonded to at least a part of the interface element (12M, 12N), wherein the at least one interface element (12M, 12N) is designed as a channel, which is designed as a keder channel and includes at least one keder hook (133) for holding a trim panel as a further component, or is designed as a cable channel for receiving a cable.including at least one obstacle for the cable.

Description

The present invention relates to a structural assembly for a vehicle seat backrest, to a vehicle seat and to a method for producing a structural assembly for a vehicle seat backrest.A structural assembly according to the preamble of claim 1 comprises a surface element. The surface element is designed and provided for forming at least a subsection of a rear wall of the vehicle seat backrest and / or for closing a cutout of a passage in the vehicle seat backrest. Furthermore, the structural assembly comprises at least one interface element which is designed and provided to produce a connection to a further component of the vehicle seat backrest, such that the further component and the structural assembly are connected to one another.The rear wall of the vehicle seat backrest regularly supports a backrest cushion, against which a seat user sitting on the vehicle seat can lean. If the vehicle seat provides one or more seats in a rear seat row of a vehicle, the rear wall of the vehicle seat backrest can face a trunk of the vehicle and / or separate it from a passenger interior.In order to be able to transport bulky goods, for example, skis, which cannot be accommodated solely in the trunk because of their length, it is known to arrange a drawer in the vehicle seat backrest. A drawer comprises a closable opening or recess. Bulky goods, such as skis, can be pushed through the opened opening or recess, so that they extend on both sides of the vehicle seat backrest.A structural assembly of the generic type in the form of a one-piece load-through component is known from DE 10 2009 040 902 A1. The charging-through component comprises a planar surface facing the trunk as a surface element and interfaces for additional components. The planar surface provides a portion of a rear wall of a vehicle seat back. The loading component is manufactured in one piece from plastic, for example as an injection-molded component in one operation, and has a low manufacturing cost with a low weight. The loading component further comprises a plurality of stiffening elements, namely stiffening ribs running diagonally to side edges of a circumferential frame of the loading component.WO 2014 / 063 838 A1 relates to a structural component made of at least one sheet metal, in particular an organosheet or metal sheet, wherein at least one surface side of the sheet metal is provided with two intersecting profile elements. In addition, this publication relates to a method for producing such a structural component.DE 10 2010 036 798 A1 describes a backrest with a base body made of plastic, wherein at least one piping channel is provided in the base body for holding a functional element. Before the plastic is blown into a mold during the production of the backrest, the piping channels are placed at a corresponding desired location of the mold and held there. The plastic is then blown into the mold, so that it flows around both anchoring ribs and at least partially a U-shaped cross section.WO2013 / 127 972 A2 and WO 2012 / 032 189 A1 each describe a method for producing a backrest rear wall.Further backrests are described in DE 10 2009 050 839 A1 and DE 199 05 215 A1.Regularly, the rear wall of a vehicle seat backrest, including a charging component which is optionally provided, is exposed to high loads in certain situations. For example, goods loaded in the trunk can exert large forces on the vehicle seat backrest in the event of severe braking of the vehicle or in the event of a frontal crash of the vehicle. In order to ensure the highest possible safety of vehicle occupants which may be present in the vehicle in situations of this type, the vehicle seat backrest should be able to withstand corresponding forces. The highest possible stability of the vehicle seat backrest, including the possibly provided loading component, is therefore desirable.It is an object of the present invention to provide an improved structural assembly.This object is achieved with the structural assembly of claim 1.According to this, it is provided that the surface element is produced from a thermoformable composite material and that the surface element is connected to at least a part of the interface element in a materially integral manner. The at least one interface element is configured as a channel. The channel is designed as a piping channel and comprises at least one piping hook for holding a further component, which is designed in particular as a cladding, or it is designed as a cable channel for receiving a cable, wherein at least one baffle is provided for the cable.According to this aspect of the present invention, the surface element is partially or alternatively completely produced from a composite material, i.e. a material of two or more materials connected to one another (in a materially bonded and / or positively locking manner). Depending on the specific material selection of the components of the material composite and the nature of the composite, such composite materials have particularly good properties with regard to their weight, their strength, rigidity and / or fracture toughness. Collectively herein, the strength, stiffness, and fracture toughness of a component are also referred to as stability. It is possible to meet particularly high stability requirements with a particularly low weight of the structural assembly. Such requirements for stability can result, for example, from the fact that the structural assembly can tolerate the forces occurring in the event of a vehicle crash and / or the forces occurring in the event of a possible misuse of the structural assembly.The channel may extend along the surface element.The channel, in particular in the form of the channel designed as a piping channel, is arranged, for example, in the region of the circumferential outer edge of the surface element (and / or of a circumferential outer edge of the structural assembly). In particular, a plurality of piping hooks can be provided. A planar, flexible cladding, in particular a fabric, plastic or leather web, can be connected to the piping channel, for example.If an optional channel is designed as an adhesive channel for receiving adhesive, a further component (e.g. the planar, flexible cladding, in particular a fabric, plastic or leather web) can be bonded to the adhesive channel by means of the adhesive received in the adhesive channel.If the channel is designed as a cable channel for receiving a cable, a cable can be held in the cable channel in a force-fit manner. At least one baffle is provided in the cable duct, for example for strain relief.Of course, the structural assembly can comprise further interface elements in addition to the at least one interface element configured as a channel, e.g. one or more further interface elements configured as a channel.The thermoformable composite material of the planar element is preferably designed as a fiber composite material, in which fibers are embedded in a matrix. Exemplary fiber diameters are in the range of a few μm or a few dozen μm, wherein materials with diameters that differ significantly from these may also be suitable. Suitable fiber materials include glass, carbon, ceramic, aramid, steel, fabric, nylon fibers and any mixtures of these and / or other fiber materials. The fiber material can be present in the form of continuous fibers. Furthermore, it can be provided that the composite material is formed as a composite of a plastic matrix, in particular a matrix of a thermoplastic (e.g. polypropylene and / or polyamide), and a fiber material embedded therein. The fiber material can be designed in the form of a fiber material piece. The fiber material piece is, for example, completely enclosed by the plastic matrix. An advantage of using a thermoplastic matrix is that such a composite material is thermoformable (thermoformable), in contrast to, for example, thermosetting fiber composites. When injection molding with plastic material, a thermoplastic can additionally melt, whereby a cohesive connection with the injection-molded plastic material is produced. Preferably, an organosheet is used as the composite material.According to a further development, the fiber material piece is designed in the form of a woven or laid scrim of fibers. It is also possible to form the fiber material piece in the form of a balanced fabric. More and / or stronger fibers in the form of warp threads can be provided than fibers in the form of weft threads (or vice versa). Alternatively or additionally, the fiber material piece can be designed as a sheared fabric. In the case of a sheared fabric, the warp threads and the weft threads enclose an angle between them (in relation to a longitudinal extension direction of the warp / weft threads), in particular 45°. It is also possible to arrange fibers in parallel or chaotically. It can also be provided to form a first region of the fiber material piece in a first of the aforementioned types and to form a second region of the fiber material piece in a second of the aforementioned types, which differs from the first. The stability of the structural assembly can thus be adapted to predetermined requirements for the load capacity.Furthermore, it is also possible to use a plurality of different composite materials in order to form the planar element wholly or partly.It can be provided that the fiber material piece of the surface element is not fully consolidated in a partial area. In particular, incomplete consolidation can be provided in a region of the materially bonded connection to the interface element. Not fully consolidated means that the fibers of the fiber material piece are present in a region with a low density than in another region and / or in a density that is lower than a nominal density of the composite material. In this way, the stability of the connection between the surface element and the interface element can be increased.Furthermore, the fiber material piece can have at least one cut-out. Thus, for example, an increased flexibility of an adjacent region of the surface element can be achieved.The interface element can be made of a different material than the surface element. The use of other materials for the interface element compared to the surface element has the advantage that correspondingly adapted, different materials are used for respectively different tasks of the components. The surface element is produced by a particularly stable material, while a more cost-effective material, for example, can be used for the interface element. Alternatively, the interface element is made of the same material as the surface element.The surface element is preferably designed in the form of a trough (at least in a cross section). For example, a circumferential edge of the surface element is bent at least partially to form a trough shape. Between the bent-over edges, the trough element can be planar at least in sections. The trough shape can increase the stability of the surface element compared to a completely planar configuration. Alternatively, it can be provided that the entire surface element extends in a planar surface.The surface element can form a receptacle. The receptacle can provide at least a part of a pivot joint bearing for connecting the structural assembly to the vehicle seat backrest. The receptacle is designed, for example, as an elongate trough. This makes it possible to achieve a particularly stable mounting of the structural assembly on the vehicle seat backrest.An edge of the surface element, in particular a circumferential outer edge, can have a C- or Z-shaped cross section at least in sections. Such a cross section can improve the stability of the surface element.The surface element and / or the interface element can have at least one predetermined breaking point. As a result, a predetermined behavior of the structural assembly can be achieved, for example, in the event of a vehicle crash.According to one embodiment, the at least one interface element is arranged in the region of the edge of the surface element, in particular in a region of the edge which has a C- or Z-shaped cross section. The interface element can be arranged in the region of an inner edge or outer edge formed by a C- or Z-shaped cross section of the edge of the surface element. Alternatively or additionally, one or more interface elements different from the at least one interface element are arranged accordingly in the region of the edge of the surface element, in particular in a region of the edge which has a C- or Z-shaped cross section.At least one further interface element can be provided and can comprise a screw dome, for example. The further component of the vehicle seat backrest can be screwed to the screw boss.Alternatively or additionally to a receptacle formed in the surface element and providing at least a part of a pivot bearing, at least one further interface element can be provided and provide a pivot bearing. The pivot bearing serves for the pivotable connection of the structural assembly to the vehicle seat backrest or for the pivotable connection of an armrest to the structural assembly.The pivot bearing can be formed with an undercut. Thus, for example, an axis of rotation (e.g. a transverse tube) can be clipped into the pivot joint bearing for prefixing. This facilitates mounting of the structural assembly on the vehicle seat backrest.The interface element, in particular the at least one further interface element, can be connected to an insert part. The insert part can constitute a part of the interface element. The insert is preferably connected to the planar element in a form-fitting manner. It is in particular made of a metal and is thus optionally particularly resilient. In this case, a jacket section of the interface element surrounds the insert part at least partially and is connected to the planar element in a materially bonded manner. The jacket section brings about the form-fitting connection of the insert part to the surface element. In this way, a secure and load-bearing connection of the insert part to the planar element can be achieved.According to a development, the insert part has at least one opening and / or depression, into which a partial region of the planar element is embossed. In this way, a particularly stable form-fitting connection can be formed in the manner of a clinching connection.In a development, the at least one further interface element is designed such that it can be connected to a headrest. The insert part can be designed as a headrest bow. The headrest bow comprises one or more, in particular two, receptacles which are designed to each receive and support a headrest rod of the headrest. Alternatively, the insert itself forms the headrest rod.In a development, at least one insert part of an interface element is designed as a threaded insert. The threaded insert can be arranged at least partially within an opening of the surface element. The further component can be screwed to the threaded insert. The threaded insert comprises an external thread and / or an internal thread. According to one variant, the threaded insert comprises a widened foot. In this case, the surface element is arranged between the widened foot of the threaded insert and the further component connected to the threaded insert. The widened foot of the threaded insert has a larger diameter than the associated opening in the surface element. The opening in the surface element is designed, for example, as a conical rim hole. The opening can be formed in such a way that fibers of a fiber material piece of the surface element do not end in the region of the opening. The fibers can be guided around the opening (displaced from the region of the opening).At least one interface element can be designed and configured for connection to an actuating element. The actuating element can be actuated, for example, for locking and / or unlocking a lock. This is in particular a lock which locks the structural assembly in a locked state with the passenger seat backrest and in an unlocked state enables pivoting of the structural assembly relative to the passenger seat backrest. The interface element can comprise at least one guide track which is configured and designed to guide the actuating element during the actuation thereof.In one embodiment variant, at least one further interface element is designed as a top-tether bracket. The top tether strap enables a connection to a seatbelt guided over the vehicle seat backrest. The top tether bracket may be made of a thermoformable composite material, in particular the same thermoformable composite material as the sheet element. The top-tether bracket can be formed by a cut-away portion of the surface element.In one embodiment variant, at least one further interface element has a spring-elastic spring element. The spring element is designed and configured to cushion an adjacent further component of the vehicle seat backrest during a relative movement between the structural assembly and the adjacent further component of the vehicle seat backrest.According to a development, the structural assembly comprises at least one stiffening element which is designed and configured to increase the stiffness of the planar element.The surface element produced from a thermoformable composite material is connected in a materially integral manner to at least one part of the stiffening element in one embodiment variant. In this way, a particularly high stability of the structural assembly can be achieved.If the composite material is formed as a composite of a thermoplastic plastic matrix and a fiber material piece embedded therein, in particular as an organosheet, it can be provided that the fiber material piece of the planar element is not fully consolidated in a region of the material-bonded connection to the stiffening element. In this way, the stability of the connection between the surface element and the interface element can be increased.The stiffening element can be made of a different material than the surface element. The use of other materials for the stiffening element compared to the surface element has the advantage that correspondingly adapted, different materials are used for respectively different tasks of the components. The surface element is produced by a particularly stable material, while a more cost-effective material, for example, can be used for the stiffening element. Alternatively, the stiffening element is made of the same material as the surface element.For example, the stiffening element and / or interface element is not made of a composite material. It can be provided that the at least one stiffening element and / or interface element comprises a plastic material, in particular consists entirely of this plastic material. Suitable materials here are polyolefins, in particular polypropylene. However, the use of plexiglass, polycarbonate, polystyrene and / or polyamide and also the use of an elastomer and / or a thermosetting plastic are also possible.In particular, the stiffening and / or interface element can be produced from the same material as the thermoplastic matrix of the composite material of the planar element.According to one embodiment variant, the stiffening element has at least one predetermined breaking point. As a result, a predetermined behavior of the structural assembly can be achieved, for example, in the event of a vehicle crash.At least one stiffening element can comprise an insert. The insert part of the stiffening element can be connected in a form-fitting manner to the planar element and in particular produced from a metal.The structural assembly unit forms, with the surface element and the at least one interface element and optionally the at least one stiffening element, a pretestable structural unit which can be mounted on a vehicle seat, in particular the backrest of the vehicle seat. The structural assembly is preferably embodied in one piece. A seat cushion, trim parts and / or further components can be connected to this assembled structural assembly.By the material-bonded connection of the surface element to the interface element and optionally to the at least one stiffening element, a particularly stable connection of the components is achieved. A cohesive connection can be produced by injection molding the surface element with a plastic. By means of a cohesive connection produced in this way, the at least one injection-molded stiffening and / or interface element does not have to be fastened to the support part in a complicated manner.The stiffening element is designed, for example, as an elongate stiffening rib. The stiffening rib extends along the surface element and protrudes therefrom. The structural assembly comprises in particular a plurality of stiffening ribs.At least one stiffening rib can have a straight course along the surface element, at least in sections. The stiffening rib extends e.g. in a plane which extends perpendicularly with respect to at least a part of the surface element. Alternatively or additionally, the reinforcing rib projects (at least in sections) at an angle from the surface element.In a development, at least one support rib is provided, which projects perpendicularly from the (in particular rectilinear) course of the stiffening rib and along the planar element. The support rib can have, in particular, an open end. The support rib forms the shape of a T with an adjacent section of the stiffening rib.The stiffening rib and / or the supporting rib can be formed in an S-, C-, L- or T-shaped cross section. In particular, by means of such cross-sectional shapes, an increased contact surface between the stiffening rib and the surface element can be achieved. An increased contact area may improve the stability of the connection. Alternatively or additionally, the stiffening rib can be designed in a curved (arched) manner. As a result, a direction of bending of the reinforcing rib under a load can be predefined.The above object is also achieved with the structural assembly of claim 26. According to this, a structural assembly for a vehicle seat backrest is provided, which structural assembly comprises a planar element which is designed and configured to form at least part of a rear wall of the vehicle seat backrest and / or to close a cutout for loading through in the passenger seat backrest, and comprises at least one stiffening element which is designed and configured to increase the stiffness of the planar element and / or at least one interface element which is designed and configured to be connected to a further component of the vehicle seat backrest. It is provided here that the surface element is produced from a thermoformable composite material and is connected in a materially integral manner to at least a part of the stiffening element and / or of the interface element, wherein the at least one interface element is designed and configured for connection to an actuating element which can be actuated for locking and / or unlocking a lock, wherein the interface element comprises at least one guide track which is designed and configured to guide the actuating element during an actuation.This makes it possible to achieve particularly secure holding of the actuating element.The lock is in particular a lock which locks the structural assembly in a locked state with the passenger seat backrest and in an unlocked state enables pivoting of the structural assembly relative to the passenger seat backrest.With regard to possible embodiments, in particular of the planar element, the at least one stiffening element and the at least one interface element, and their connection to one another, reference is made to the explanations relating to the first-mentioned aspect of the present invention.According to another aspect of the present invention, there is provided a vehicle seat for a motor vehicle, comprising a backrest having a structural assembly according to any embodiment described herein.The above object is also achieved by the method of claim 28. Thereafter, a method of manufacturing a structural assembly for a vehicle seat backrest is provided. The method comprises the following steps:providing a surface element which is designed and configured to form at least a part of a rear wall of the vehicle seat backrest and / or to close a cutout of a passage in the passenger seat backrest, andproviding at least one interface element which is designed and configured for connection to a further component of the structural assembly.It is provided that:the planar element is produced from a thermoformable composite material, andthe surface element is connected to at least a part of the interface element in a materially integral manner, wherein the at least one interface element is configured as a channel, which is connected to at least a part of the interface element in a materially integral manner.is designed as a piping channel and comprises at least one piping hook for holding a cladding as a further component, ora cable channel for receiving a cable, wherein at least one baffle is provided for the cable.Depending on the choice of the materials specifically used, a particularly light and stable structural assembly can be created. In particular with regard to the selection and configuration of the specific materials used in the method and the corresponding advantages, reference is made to the above description with regard to the materials of the structural assembly.In order to produce a cohesive connection between the at least one interface element and the surface element, there are in principle several possibilities, such as, for example, adhesive bonding or welding of the components or the like. In particular, the interface element can be injection-molded onto the surface element by injection molding. During the injection molding, for example, the same material as that of a thermoplastic matrix of the planar element is used.In a development, two-component injection molding is used. A component of two-component injection molding can be an elastomer, e.g. in order to form elastic elements for tolerance compensation. For another component, the same material can be used as for a thermoplastic matrix of the planar element.During the injection molding, at least one insert (insert) can be injection molded. The insert is then connected to the planar element in a form-fitting manner. The insert is preferably made of metal (e.g. steel). Alternatively, the insert part can be produced from an elastomer, from a plastic (e.g. the same plastic as is also used for the thermoplastic matrix of the planar element) or from a thermoformable composite material (in particular organosheet).During the forming of the composite material, a section of the composite material can be embossed into an opening or depression of an insert, for example with the aid of a correspondingly formed mandrel. An injection molding or over-molding of the insert part can take place following the forming. This makes it possible to produce a particularly stable form-fit and material-fit connection of the insert part to the surface element in the manner of a clinching connection.The composite material can be formed as a composite of a thermoplastic plastic matrix and a fiber material piece embedded therein. At least one opening can be formed in the surface element. To form the opening, fibers of the fiber material piece can be displaced essentially non-destructively. In this way, it is possible to form an opening in the surface element passing through the fiber material piece without substantially impairing the stability of the surface element.In a development of the method, at least one stiffening element is provided, which is designed and configured to increase the stiffness of the surface element.In one embodiment variant, the surface element produced from a thermoformable composite material is connected, in particular bonded, to at least part of the stiffening element.According to one embodiment variant, the stiffening element is injection-molded onto the surface element by injection molding, in particular by means of a two-component injection molding method.With regard to the connection of the at least one stiffening element to the surface element, reference is made to the above explanations with regard to the connection of the at least one interface element to the surface element, which correspondingly apply to the stiffening element.The stiffening element and / or the interface element can be injection-molded onto the surface element in such a way that a sharp edge is produced at the transition between the stiffening element / interface element and the surface element (e.g. an edge with an acute angle). The stiffening element and / or the interface element can be formed, in particular for this purpose, with a chamfer adjoining the surface element or a shoulder adjoining the surface element. A particularly clean tool seal of an injection molding tool can be achieved by a sharp edge.In a development of the method, during the injection molding of the stiffening element and / or interface element onto the surface element, a surface of the surface element in contact therewith is heated and fused. Such a fusing assists the establishment of a cohesive connection.A simplification of the production method of the structural assembly can be achieved if both the forming of the composite material and the injection molding of the at least one stiffening and / or interface element onto the surface element take place in the same (injection molding) tool, in particular in a one-shot process. In this case, the composite material can be heated before being inserted into the injection mold and / or in the injection mold. The forming can be effected by the injection molding tool and / or by the action of the injected injection molding compound.The composite material can be cut to size in a desired shape in order to form the planar element from this material blank (and optionally additional components to be connected thereto). The blank can be, but does not necessarily have to be, before the connection to the at least one stiffening element and / or interface element.During the production of the planar element, the thermoformable composite material can be shaped by means of thermoforming.According to another aspect of the present invention, a method of manufacturing a structural assembly for a vehicle seat backrest is provided. The method comprises the following steps:providing a surface element which is designed and configured to form at least a part of a rear wall of the vehicle seat backrest and / or to close a cutout of a passage in the passenger seat backrest, andproviding at least one stiffening element, which is designed and configured to increase the stiffness of the surface element, and / or at least one interface element, which is designed and configured to be connected to a further component of the structural assembly.It is provided that:the planar element is produced from a thermoformable composite material, andthe surface element is connected to at least a part of the stiffening element and / or the interface element in a materially bonded manner,wherein the at least one interface element is designed and configured for connection to an actuating element which is actuatable for locking and / or unlocking a lock, wherein the interface element comprises at least one guide track which is designed and configured to guide the actuating element upon actuation.Depending on the choice of the materials specifically used, a particularly light and stable structural assembly can be created. In particular with regard to the selection and configuration of the specific materials used in the method and the corresponding advantages, reference is made to the above description with regard to the materials of the structural assembly.A structural assembly according to the invention can also be produced by a method according to the invention for producing a structural assembly. The features and advantages of a method according to the invention for producing a structural assembly, explained above and still illustrated below, thus also apply to a structural assembly according to the invention and vice versa.Further advantages and features of the present invention will become apparent from the following description with reference to the figures.The following are shown: FIG. 1 shows an exemplary embodiment of a structural assembly according to the invention with a plurality of stiffening elements and a plurality of interface elements in a perspective view; FIG. 2 shows a plan view of a front side of the structural assembly according to FIG. 1 ; FIG. 3 shows a plan view of a rear side of the structural assembly according to FIGS. 1 and 2 and an enlarged detail of the plan view; FIG. 4 shows a cut-away view of the structural assembly according to the sectional plane A-A illustrated in FIG. 2 ; FIG. 5 shows an enlarged detail of the view according to FIG. 4 ; FIG. 6 shows a cut-away view of the structural assembly according to the sectional plane B-B illustrated in FIG. 1 ; FIG. 7 is a view of plane C-C shown in FIG. 2 from a lower portion of the structural assembly; FIG. 8 shows a view of the plane D-D shown in FIG. 2 from a lower portion of the structural assembly with a supporting arm of the vehicle seat backrest connected thereto; FIG. 9 shows a cut-away view of the structural assembly according to the sectional plane E-E illustrated in FIG. 2 ; FIG. 10 shows a cut-away view of the structural assembly according to the sectional plane F-F illustrated in FIG. 1 ; FIG. 11 shows a plan view of an outer side of a lock of the structural assembly according to FIGS. 1 to 10 ; FIG. 12 shows a top view of an inner side of the lock according to FIG. 11 ; FIG. 13 shows a cut-away view of the lock according to the sectional plane G-G shown in FIG. 12 ; FIG. 14 is a side view of the structural assembly according to FIGS. 1 to 13; FIG. 15 shows an exemplary embodiment of an insert part connected to a planar element of a structural assembly; FIG. 16 shows a further exemplary embodiment of an insert part connected to a planar element of a structural assembly; FIG. 17 shows a further exemplary embodiment of an insert part connected to a surface element of a structural component; FIG. 18 shows a cross section of a connection region of a stiffening element to a surface element of a structural assembly; and FIG. 19 shows a plan view of a rear side of a structural assembly.FIGS. 1-3 illustrate the general construction of a vehicle seat backrest structural assembly 1 of a seat assembly of a vehicle. The structural assembly 1 comprises a flat and planar surface element 10. These increase the rigidity of the surface element 10, for example, against bending, twisting and / or against breaking of the surface element 10 under load. Furthermore, a plurality of interface elements 12A- 12R are connected to the surface element 10 in a materially integral manner. These serve in each case for connecting the structural assembly 1 to a further component of the seat arrangement.The structural assembly 1 is designed in the form of a loading device which can be arranged, for example, on the backrest of a rear seat arrangement of the vehicle. The backrest of the rear seat assembly separates a trunk from a passenger compartment of the vehicle and includes a (loading) recess. For example, bulky cargo may be transported extending through the recess. The recess can also allow access to cargo accommodated in the trunk from the passenger interior. The structural assembly 1 is provided to close the recess in a closed state and can be transferred, if required, into an open state in which it at least partially exposes the recess.When in the closed state, the structural assembly 1 provides a part of the backrest. A seat user may lean against the structural assembly 1. For this purpose, the structural assembly 1 is provided with a cushion, not shown in the figures.The structural assembly 1 is connected to a plurality of further components of the vehicle seat backrest. In the present case, an armrest carrier 2 and a lock 3 are fastened to the structural assembly 1. Furthermore, the structural assembly 1 can be connected to further components not shown in FIGS. 1 to 3, namely in particular to a plurality of cladding parts, a transverse tube for connecting the structural assembly 1 to the vehicle seat backrest, a headrest and cables.The structural assembly 1 has two outer side edges 16A, 16B, namely a left side edge 16A, which is shown in the view of the front side of the structural assembly 1 shown in FIG. 1, and an opposite right side edge 16B.The side edges 16A, 16B adjoin adjacent regions of the backrest when the structural assembly 1 closes the cutout of the backrest as intended. Furthermore, the structural assembly 1 has an upper end edge 16C and a lower end edge 16D, which together with the side edges 16A, 16B describe substantially the shape of a rectangle in plan view of the front side. The side edges 16A, 16B are longer than the upper and lower end edges 16C, 16D. The structural assembly 1 is designed in such a way that the upper end edge 16C ends essentially flush with adjacent upper end edges of adjacent regions of the backrest when the structural assembly 1 closes the cutout of the backrest as intended. The lower end edge 16D abuts a seating surface of the seat assembly.In a region B 1 adjoining the lower end edge 16D, the structural assembly 1 is tapered, such that the lower end edge 16D is shorter than the upper end edge 16C. The tapered region B 1 is offset (step-like) from a non-tapered region B 2 in the direction of a seat user seated on the seat arrangement.The planar element 10 extends substantially over the entire surface between the side edges 16A, 16B and the upper and lower end edges 16C, 16D. The planar element 10 is produced from a material composite of a thermoplastic plastic matrix with a fiber material piece embedded therein, specifically from organosheet.The stiffener members 11A- 11P and the interface members 12A- 12R are not made of organo-sheet. The stiffener members 11A- 11P and the interface members 12A- 12R are made of a thermoplastic resin material. In the present case, the thermoplastic material of the stiffening and interface elements 11A- 11P, 12A- 12R is the same material as in the thermoplastic matrix of the planar element 10, for example polypropylene. The stiffening elements 11A- 11P and the interface elements 12A- 12R are (at least partially) injection-molded onto the planar element 10 by injection molding. The surface element 10 is thus embodied in one piece, but from different materials.The structural assembly 1 comprises a plurality of stiffening elements in the form of stiffening ribs 11A-11D, 11F-11H, 11N. In this case, reinforcing ribs are arranged both on the front side visible in FIGS. 1 and 2 and on the rear side of the structural assembly 1 shown in FIG. 3. When the structural assembly 1 is intended to close the recess of the backrest of the seat arrangement, the front side of the structural assembly 1 faces a seat user seated on the seat arrangement. The rear side of the structural assembly 1 then faces the trunk of the vehicle. The rear side of the structural assembly 1 is in particular substantially planar in the tapered region B 1 and in the non-tapered region B 2. In the non-tapered region B 2, reinforcing elements 11E- 11G, 11L are provided on the rear side of the structural assembly 1 only in edge regions.The totality of the stiffening ribs 11A- 11D arranged on the front side of the structural assembly 1 extends substantially over the entire height and width of the planar element 10, as can be seen in particular with reference to FIG. 2. The stiffening ribs 11A- 11D project from the surface element 10. The stiffening ribs 11A- 11D describe, at least in sections, a rectilinear shape. In this case, a plurality of vertical stiffening ribs 11A are provided, which extend parallel to the side edges 16A, 16B. Further, a plurality of horizontal reinforcing ribs 11B are provided which extend parallel to the upper and lower end edges 16C, 16D (and perpendicular to the vertical reinforcing ribs 11A). The structural assembly 1 further comprises a plurality of right-inclined stiffening ribs 11C which are inclined substantially by 45° with respect to the vertical and horizontal stiffening ribs 16A, 16B (to the right in the view according to FIG. 2 with respect to the vertical stiffening ribs 11A). Furthermore, a plurality of left-inclined stiffening ribs 11D are provided, which extend perpendicularly to the right-inclined stiffening ribs 11C.A plurality of reinforcing ribs 11A-11D are respectively aligned parallel to each other. Differently oriented stiffening ribs 11A-11D cross each other at a plurality of crossing points K.In the present case, the stiffening ribs 11A- 11D are arranged on the front side of the structural assembly 1 in such a way that a cross region B 3 is produced in which a plurality of right-inclined stiffening ribs 11C and a plurality of left-inclined stiffening ribs 11D are arranged in the form of a grid and form a multiplicity of crossing points K. The cross portion B 3 is disposed adjacent to the lower end edge 16D. A majority of the cross region B 3 extends in the tapered region B 1 of the structural assembly 1. In the tapered region B 1, the reinforcing ribs 11C, 11D can be subjected to a compressive load when the structural assembly 1 is used in the vehicle seat backrest. The compressive load can be exerted, in particular in the event of a rear-end crash of the vehicle, by a seat user resting on the structural assembly 1.In particular in the case of a rear-end crash of the vehicle, a force can be exerted on the front side of the structural assembly 1 by a seat user. Such a force can in particular lead to a deformation of the surface element 10. During such a deformation, the reinforcing ribs 11D arranged on the front side of the structural assembly 1 in a central and / or upper region of the planar element 10 are stretched along their longitudinal extent (subjected to a tensile load). In this region, the stiffening ribs 11D are formed predominantly parallel and without crossing points (or with only a few crossing points per unit area in comparison with the crossing region B 3) and form a parallel region B 4.In the parallel region B 4, a plurality of support ribs 110 are arranged. The support ribs 110 are each integrally connected to a left-inclined reinforcing rib 11D. The supporting ribs 110 project substantially perpendicularly from the connected reinforcing rib 11D and have an open end 111 at their section facing away from the reinforcing rib 11D. The open end 111 is not connected to a stiffening rib 11A-11D. The supporting ribs 110 are shorter, as seen along the planar element 10, than the distance between the connected reinforcing rib 11D and the next adjacent parallel reinforcing rib 11D.The parallel region B 4 is arranged above the cross region B 3 when the structural assembly 1 is used as intended in its closed state. An (imaginary) diagonal between the lock 3 and a left lower corner of the structural assembly 1 (between the left side edge 16A and the lower end edge 16D) describes an upper triangle and a lower triangle of the structural assembly 1. The cross portion B 3 is disposed substantially inside the lower triangle.The structural assembly 1 is reinforced in particular by the parallel region B 4 against bending in the region of a left upper corner of the structural assembly 1 (between the left side edge 16A and the upper end edge 16C). The support ribs 110 prevent the stiffening ribs 11D from bending laterally.Alternatively or additionally, supporting ribs 110 can also be provided on vertical, horizontal and / or right-inclined reinforcing ribs 11A- 11C.In the tapered region B 1 and in the non-tapered region B 2, the planar element 10 is substantially planar and has edges 101 bent over toward the front side. The planar sections of both regions B 1, B 2 are aligned parallel to one another. The tapered region B 1 and the non-tapered region B 2 merge into one another in a step-like transition region B 5. As can be seen in particular by viewing FIGS. 1 and 2 together, the stiffening ribs 11A- 11D project substantially perpendicularly from the surface element 10 in the tapered and non-tapered regions B 1, B 2. In the transition region B 5, the stiffening ribs 11A- 11D protrude from the planar element 10 in such a way that they extend in planes which are oriented perpendicularly to the planar regions of the planar element 10 in the tapered and in the non-tapered region B 1, B 2. Both in planar and in uneven regions of the surface element 10, the stiffening ribs 11A-11D extend perpendicularly to the planar regions of the surface element 1.The edge 101 of the planar element 10 is provided with a stiffening element in the form of an edge reinforcement 11E, 11K. The edge reinforcement 11E is made of the same material as the reinforcing ribs 11A-11D, 11F-11H, 11N.On the rear side of the planar element 10 (see FIG. 3 ), reinforcing elements in the form of reinforcing ribs 11H are provided in the tapered region B 1 of the structural assembly 1. In this case, a plurality of crosses are provided, which are formed by two reinforcing ribs 11H in each case, the cross being framed by further reinforcing ribs 11H. A plurality of such framed crosses are arranged in a row. Adjacent to the row of framed crosses of stiffening ribs 11H, further crossed stiffening ribs are arranged, wherein a plurality of crosses are framed together by further stiffening ribs 11H. Adjacent to the lower end edge 16D, a plurality of reinforcing ribs 11H are disposed along the lower end edge 16D so as to form a zigzag shape.On the rear side of the surface element 10, further stiffening elements are provided on non-planar regions of the surface element 10. At the side edges 16A, 16B of the structural assembly 1, the planar element 10 is bent over in the direction of its front side. In FIG. 3, a detail A of a part of the side edge 16A of the structural assembly 1 is shown in an enlarged manner. In this region, the edge reinforcement 11E is provided with a plurality of longitudinal ribs 11F. The longitudinal ribs 11F extend parallel to the side edges 16A, 16B. A plurality of connecting ribs 11G extend perpendicularly to the longitudinal ribs 11F. The connecting ribs 11G are arranged in a plurality of (in the present case two per side edge 16A, 16B) rows. In this case, the connecting ribs 11G of one row are arranged offset with respect to the connecting ribs 11G of an adjacent row.Similarly, portions of the back side of the transition region B 5 where the planar element 10 is bent are also provided with reinforcing elements. There, only a row of connecting ribs 11G is provided.FIG. 4 shows a cut-away view of the structural assembly 1. it can be seen therein that the edges 101 of the planar element 10 are bent over towards the front side at the side edges 16A, 16B of the structural assembly 1. Between the edges 101 the surface element 10 is substantially planar. The edges 101 comprise a flange 105 directed outwards in each case, which is arranged substantially parallel to the planar section of the planar element 10 between the edges 101. The edges 101 of the planar element 10 are thus approximately Z / S-shaped. The flange 105 forms an inner edge 102 with the remaining edge 101 of the surface element 10.In cross section, the surface element 10 substantially has a trough shape. By the described configuration of the edges 101 of the planar element 10, a particularly high stability of the structural assembly 1 can be achieved.In the region of the upper end edge 16C and the lower end edge 16D, the edge 101 of the planar element 10 is not bent over.It can also be seen in FIG. 4 that the support ribs 110 each have a bevel 112. The slope 112 extends between the connected left-inclined stiffening rib 11D and the open end 111 of the support rib 110. The slope 112 forms the edge of the support rib 110 facing away from the surface element 10. This makes it possible to save material and thus reduce the weight of the structural assembly 1.Some (or alternatively all) stiffening elements 11A- 11P comprise a widened base 113 in the region of their materially bonded connection to the planar element 10. It can be seen in FIG. 4 that the left-inclined stiffening ribs 11D and the supporting ribs 110 each comprise such a widened base 113. The widened bases 113 make it possible to achieve a particularly stable connection of the reinforcing elements 11A- 11P to the planar element 10.FIG. 5 shows an enlarged detail of the view according to FIG. 4 in the region of the left side edge 16A. It can be seen in particular with reference to FIG. 5 that the surface element 10 is provided on its circumferential end edge 106 with a stiffening element in the form of an end edge edging 11J. The end edge seam 11J covers the end edge 106 as well as areas of the flange 105 adjacent to the end edge 106. The end edge bead 11J is provided wherever the end edge 106 of the panel 10 is not already otherwise joined. The end edge bead 11J protects the end edge 106 from damage.In the region of the end edge edging 11J, the fiber material piece of the planar element 10 is not fully consolidated (pleated). The individual fibers of the fiber material piece thus lie less closely against one another than in fully consolidated regions. As a result, a particularly stable connection of the end edge edging 11J to the planar element 10 can be achieved.FIG. 5 also shows that a plurality of interface elements 11M, 11N for connection to a trim part are formed on the edge reinforcement 11E on the rear side of the structural assembly 1. The interface elements 11M, 11N serve in particular for connecting to a flat, flexible cladding part, preferably a carpet.As FIGS. 1, 3 and 5 illustrate in particular, an interface element in the form of a piping channel 12M is provided on the outer edge of the edge reinforcement 11E. The piping channel 12M is designed and configured to receive the flat, flexible cladding part. The piping channel 12M extends along the side edges 16A, 16B, the top end edge 16C, and / or the bottom end edge 16D. Along the piping channel 12M, a plurality of piping hooks 133 are disposed inside the piping channel 12M. The piping hooks 133 are designed to hold the flat, flexible covering part. For improved flexibility of the piping hooks 133, these are partially cut free. The piping channel 12M is connected to the surface element 10 in a materially integral manner.Adjacent the piping channel 12M, an adhesive channel 12N is disposed. The adhesive channel 12N extends substantially parallel to the piping channel 12M. The adhesive channel 12N is designed and configured to receive adhesive for an adhesive connection of the flat, flexible cladding part to the structural assembly 1.The piping channel 12M and / or the adhesive channel 12N can alternatively or additionally also serve as a cable channel for receiving a cable.For the connection to the lock 3, the planar element 10 comprises a tab 108 bent over towards the front side of the planar element 10. A stiffening element in the form of a stiffening frame 11M is connected to the tab 108 of the planar element 10 in a materially integral manner. The stiffening frame 11M frames edges of the tab 108 and at least partially covers the tab 108 on its side facing the lock 3. The stiffening frame 11M increases the stiffness of the tab 108 of the planar element 10. A plurality of horizontal stiffening ribs 11B abut and support the tab 108. For this purpose, two of the horizontal stiffening ribs 11B are raised toward the tab 108.The structural assembly 1 is designed and configured to deform under a load such that a bulge counteracting the deformation is formed. This can be effected by a corresponding alignment of a plurality of fiber layers of the fiber material piece of the planar element 10 and / or a corresponding arrangement of the stiffening elements 11A- 11P. In this way, in particular in the event of a frontal crash, a forward displacement of sections of the structural assembly 1 can be reduced.As already mentioned, the structural assembly 1 comprises a plurality of interface elements 12A- 12R.As FIGS. 1, 2 and 6 illustrate in particular, a plurality of interface elements are each designed as a screw dome 12A for connection to a central armrest. In the present case, the structural assembly 1 comprises four screw domes 12A for connection to the central armrest.The screw domes 12A are connected thereto on the front side of the surface element 10 in a materially integral manner. The screw domes 12A are substantially hollow cylindrical in shape with a circular cross section. The screw domes 12A each comprise a widened base 120 for stable materially bonded connection to the planar element 10. The screw domes 12A each comprise a threaded bushing 122 having an internal thread and an external thread. The threaded bushes 122 are each screwed with their external thread into the associated screw dome 12A.An armrest support 2 comprises two brackets 21 for the pivotable mounting of the center armrest, which is not otherwise shown in the figures. By means of four screws 20, which are each screwed to the internal thread of the threaded bushes 122, the armrest support 2 is fastened to the structural brewing assembly 1.Positioning pins 12B allow prepositioning by cooperation with associated positioning holes in the armrest carrier 2 during the mounting of the armrest carrier 2 on the structural assembly 1. The positioning pins 12B are connected to the surface element 10 in a materially integral manner via the stiffening ribs 11A- 11D.In an alternative embodiment, the threaded bushes 122 are not screwed into the associated screw domes 12A, but rather are designed as an insert part and connected in a positive-locking manner to the respective screw dome 12A. The positive connection is effected by injection molding around the threaded bushes 122, forming the screw domes 12A.With reference in particular to FIGS. 1 to 3 and 7 to 9, a further interface element 12C of the structural assembly 1 will now be described. This interface element is designed as a pivot joint bearing 12C and establishes a connection of the structural assembly 1 to a transverse tube 4 of the vehicle seat backrest.The pivot bearing 12C is disposed near the lower end edge 16D. It allows the structural assembly 1 to be pivoted relative to the rest of the vehicle seat between the open and the closed state.The pivot joint bearing 12C comprises a plurality of (in the present case two) receptacles 123 for bearing the transverse tube 4. the receptacles 123 are each connected in one piece to the edge reinforcement 11K in the region of the tapered region B 1 and are produced from the same material.FIG. 7 shows a view of the left side edge 16A of the structural assembly 1 in the region of the lower end edge 16D. The receptacle 123 forms an undercut 124. FIG. 8 shows the receptacle 123 on the right side edge 16B, which likewise forms an undercut 124. If the transverse tube 4 is introduced into the receptacles 123, it locks with the undercuts 124. The structural assembly 1 is then connected to the cross tube 4 and can be secured thereto by two sheet metal clamps 40.While FIG. 7 shows the receptacle 123 and the sheet metal clamp 40, but not the transverse tube 4, the latter is shown mounted in the receptacles 123 in FIG. 8. Two support arms 42 arranged on both sides of the structural assembly 1 are connected to the transverse tube 4. The support arms 42 are mounted on the vehicle seat for connecting the transverse tube 4 to the vehicle seat. The transverse tube 4 provides a pivot axis S about which the structural assembly 1 connected to the transverse tube 4 is pivotable.FIG. 9 shows a cut-away view of the structural assembly 1 in the region of the transverse pipe 4 connected thereto. One of the sheet metal clamps 40 can be seen therein, which wraps around the transverse pipe 4 and is fastened to the structural assembly 1 by means of two screws 41. The screws 41 are in the present case FDS screws which can connect the surface element 10 to the sheet metal clamp 40 without pre-perforation.Furthermore, it can be seen in particular in FIG. 9 that the surface element 10 likewise forms a receptacle 100. The receptacle 100 of the planar element 10 is designed in the form of a channel-like depression which extends between the receptacles 123 at the side edges 16A, 16B of the structural assembly 1. Together, the receptacles 123, 100 form the pivot joint bearing 12C on the side edges 16A, 16B of the structural assembly 1 and of the planar element 10. The receptacle 100 of the surface element 10 can also be seen in particular in FIG. 1.The structural assembly 1 further comprises a plurality of interface elements in the form of latching domes 12Q for connection to at least one cladding or panel (see in particular FIGS. 1 and 2 ). The latching domes 12Q comprise a widened base, via which they are connected to the planar element 10 in a materially integral manner. The latching domes 12Q are substantially circular-cylindrical. A cylinder axis of the latching domes 12Q is aligned substantially perpendicular to adjacent sections of the planar element 10. In the present case, five locking domes 12Q are provided. Each of the locking domes 12Q can be connected in a locking manner to an associated connecting counterpart. Alternatively, the locking domes 12Q can also be designed as screw domes which can be brought into engagement with a screw.FIG. 10 shows a cut-away view of the structural assembly 1 in a region adjacent to the upper end edge 16C. The structural assembly 1 comprises two headrest holders 12D, as can be seen in particular by viewing FIGS. 1, 3 and 10 together. Each of the headrest brackets 12D is configured and configured to receive and support a headrest rod of a headrest.Each of the headrest brackets 12D includes three receptacles 125A- 125C. The receptacles 125A- 125C are arranged spaced apart along a longitudinal axis of the structural assembly 1 extending parallel to the side edges 16A, 16B. The head restraint rod may be inserted into the receptacles 125A- 125C. The receptacles 125A- 125C of each of the headrest supports 12D are coaxially aligned with one another.A first receptacle 125A of both headrest holders 12D is formed by a common headrest bow 126. The headrest bow 126 is a material strip bent over at a multiple substantially right angle (in particular a metal strip). The headrest bow 126 abuts the planar element 10. It is formed as an insert. The headrest bow 126, with the exception of those regions which form the first receptacles 125A, is completely surrounded by the planar element 10 and a stiffening surface 11P which is connected to the planar element 10 in a materially integral manner. The stiffening surface 11P forms a surface covering the headrest bow 126, from which a plurality of (beveled) vertical stiffening ribs 11A extend. Thus, the headrest bow 126 is connected to the surface element 10 in a form-fitting manner.By forming the headrest bow 126 from metal, a particularly stable mounting of the headrest can be achieved.In the region of the first receptacles 125A, the planar element 10 is provided with a cutout 107, in each of which a reinforcing element in the form of a reinforcing insert 11L is inserted. Each of the stiffening inserts 11L extends into the bent-over regions of the headrest bow 126 also forming the first receptacles 125A. The stiffening inserts 11L thus form part of the first receptacles 125A. On its side facing away from the first receptacle 125A, each of the stiffening inserts 11L comprises a plurality of vertical and horizontal stiffening ribs.A second receptacle 125B of both head restraint mounts 12D is formed by one of the horizontal stiffening ribs 11B. The horizontal stiffening rib 11B is oriented parallel to the headrest bow 126 and is arranged at a distance therefrom. In the region of the second receptacles 125B, the horizontal stiffening rib 11B is reinforced on one side and thus forms a rim hole. The horizontal stiffening rib 11B forming the second receptacles 125B is generally higher (as viewed from the planar element 10) than the adjacent stiffening ribs 11A, 11B, 11D.The first and second receptacles 125A, 125B are substantially formed as square openings.A third receptacle 125C of both headrest holders 12D is formed by a further horizontal reinforcing rib 11B. The third receptacles 125C are formed in the form of depressions in said horizontal stiffening rib 11B.FIGS. 11 to 13 show different views of a connection of a lock 3 to an interface element in the form of a lock holder 12E of the structural assembly 1. the lock 3 has a locked state and an unlocked state and is designed and configured to lock with an associated locking element of the vehicle seat backrest in the locked state. In the locked state of the lock 3, the structural assembly 1 is not pivotable about the pivot axis S with respect to the vehicle seat backrest.To effect a locking, the lock 3 comprises a lock mechanism 30, which cooperates in a locking manner with the associated locking element in the locked state of the lock 3. The lock 3 further comprises a button 31. the button 31 is operatively connected to the lock mechanism 30. By actuating the button 31, the lock 3 is transferred from the locked state into the unlocked state.The lock holder 12E is arranged on the bent-over tab 108 of the planar element 10. The tab 108 protrudes substantially perpendicularly from adjacent planar portions of the planar element 10. A region of the planar element 10 between an origin of the tab 108 on the planar element 10 and the next adjacent vertical stiffening rib 11A is offset with respect to adjacent planar sections of the planar element 10 (in the form of a step).Two openings are provided in the tab 108, into each of which a metal insert 128 is inserted. Each of the two metal inserts 128 of the lock holder 12E is penetrated by a screw 32 of the lock 3. The screws 32 are each in engagement with an associated thread of the lock 3 in order to retain the lock 3 on the structural assembly 1. On the side of the tab 108 of the planar element 10 opposite the lock 3, a securing nut 33 is provided, which is passed through in front of the screw 32 and secures the respective metal insert 128 on the tab 108. FIG. 12 shows the side of the tab 108 of the planar element 10 facing away from the lock 3 without the securing nuts 33.The metal insert 128 has a circular cylindrical shank and a flange running around the lateral surface of the shank. The flange rests on the tab 108 of the surface element 10 (i.e. on the organic sheet) and is supported thereon. The flange is recessed from an end face of the shank approximately by the thickness of the tab 108. The end face of the shank of the metal insert 128 thus terminates flush with a surface of the tab 108 opposite the flange of the metal insert 128. The flange of the metal insert 128 supports the metal insert 128 against tilting relative to the tab 108. The lock mechanism 30 (or a part of the lock mechanism 30) is rotatably mounted on the metal insert 128.The lock holder 12E furthermore forms (in the present case two) guide tracks 127, which are designed and configured to guide associated guide pins 310 of the button 31. The guide tracks 127 permit displacement of the button 31 upon actuation thereof.The structural assembly 1 comprises a plurality of interface elements for guiding and holding cables in the form of cable clamps 12F, cable holders 12G and cable guides 12H, 12J. Cables serve, for example, for supplying power and / or controlling the headrest, the lock 3 and / or further components connected or connectable to the structural assembly 1.FIG. 1 shows a plurality of cable clamps 12F each having two clamp sections which are designed to receive a cable and to hold it between the clamp sections in a force-fit manner. The cable clamps are formed on upper edges of a plurality of stiffening ribs 11A, 11D facing away from the surface element.A cable holder 12G comprises three pins which project perpendicularly from the planar element 10 or a stiffening rib 11A, 11B. The pins are arranged substantially in a row and are designed to hold a cable alternately guided through the pins in a force-fitting manner (spring-elastically). The cable holders 12G form a baffle for the cable.A first cable guide 12H is disposed in the region of a lower corner between the left side edge 16A and the lower end edge 16D. The first cable guide 12H is configured to receive and guide a cable from the rear side of the structural assembly 1 to the front side of the structural assembly 1.FIG. 14 shows a course of a second cable guide 12J along the left side edge 16A of the structural assembly 1. the second cable guide 12J extends along the edge 101 of the planar element 10 adjacent to the inner edge 102. The second cable guide 12J is arranged below a Z-turn of the edge 101. As a result of this arrangement, the cable is particularly well protected by the flange 105 of the planar element 10 and the edge reinforcements 11E, 11K.It can also be seen in FIG. 14 that the surface element 10 has an S-shaped twist (or Z-shaped twist, depending on the viewing direction) or an S- or Z-shaped cross-sectional profile. The tapered region B 1 shown on the right in FIG. 14 is offset (step-like) relative to the non-tapered region B 2 shown on the left. The S-impact of the surface element 10 can absorb energy when the structural assembly 1 is loaded.FIGS. 15 and 16 show two variants of interface elements in the form of screw connections 12K, 12L for use on a structural assembly such as the structural assembly 1 according to FIGS. 1 to 14, for example for connecting the structural assembly 1 to a central armrest.The threaded connections 12K, 12L each include a threaded insert 129A, 129B having a widened foot 130A, 130B. The screw insert 129A, 129B extends through an opening 103 in the surface element 10 at the opening 103, the surface element 10 is bent open to form a channel. The opening 103 in the planar element 10 is formed at a depression 104, in which the foot 130A, 130B of the respective screw insert 129A, 129B is received. The depression 104 forms together with the opening 103 a conical passage.The widened foot 130A, 130B of the respective screw insert 129A, 129B has a larger diameter than the opening 103 in the planar element 10. In this way, the screw inserts 129A, 129B are secured particularly well to the planar element 10. As a result of the depression 104, the foot 130A, 130B does not protrude from the planar element 10.While the screw insert 129A according to FIG. 15 is designed as a threaded bolt with an external thread, the screw insert 129B according to FIG. 16 is designed as a threaded bushing with an internal thread.On the side of the planar element 10 opposite the foot 130A, 130B, both variants of the screw insert 129A, 129B are encapsulated by injection molding material 131 on a casing section adjoining the planar element 10. The injection-molding material 131 is connected to the surface element 10 in a materially integral manner. The foot 130A of the screw insert 129A of FIG. 15 is overmolded with injection molding material 131. The cavity 104 is partially filled with injection molding material 131 (alternatively, the cavity 104 is completely filled with injection molding material 131). In a variant, not shown, the foot 130B of the screw insert 129B according to FIG. 16 is also over-molded with injection-molding material 131.FIG. 17 shows an interface element in the form of a holder 12P for use on a structural assembly such as the structural assembly 1 according to FIGS. 1 to 14 In the present case, the holder 12P is connected by way of example to a rod 5. The rod 5 is, for example, a headrest rod of a headrest. The rod 5 comprises a depression 50. The surface element 10 is stamped into the depression 50. This is effected, for example, with the aid of a corresponding mandrel. In the region of the depression 50, the rod 5 rests on a raised, beveled region of the surface element 10 and is surrounded by injection-molded material 131 injection-molded thereon. By the surface element 10 being impressed into the depression 50, a particularly stable connection of the rod 5 to the structural assembly 1 takes place, similar to a clinching connection.Alternatively, the rod 5 comprises a plurality of depressions 50 and / or one or more holes into which the planar element 10 is embossed. The stamping of the surface element 10 into a depression or a hole can be provided when connecting to any desired insert part or other component, in particular the headrest bow 126 of the structural assembly 1 of FIGS. 1 to 14.FIG. 18 shows a cross section of a stiffening element in the form of a stiffening rib 11N. The stiffening rib 11N is connected to the surface element 10 made of organosheet and projects substantially perpendicularly therefrom. In the region of its connection to the surface element 10, the stiffening rib 11N has a widened base 113. The widened base 113 increases the contact surface at which the reinforcing rib 11N is connected to the planar element 10 compared to a reinforcing rib without a widened base. The connection is particularly stable due to the enlarged contact surface. In cross section, the stiffening rib 11N has the shape of a T.Below the contact surface between the stiffening rib 11N and the surface element 10, the fiber material piece of the surface element 10 is not fully consolidated. The fibers of the fiber material piece are arranged below the contact surface at a greater distance from one another than in adjacent regions. Due to the incomplete consolidation of the fiber material piece on the contact surface, the material connection of the stiffening rib 11N to the surface element 10 is particularly stable. The fiber material piece is embedded in a thermoplastic matrix. The stiffening rib 11N is made of the same material as the plastic matrix.The connection of any stiffening element 11A- 11P and / or interface element 12A- 12R described herein to the planar element 10 may be carried out according to the connection shown in FIG. 18 to a widened base and / or to a not fully consolidated region of the planar element 10.FIG. 19 shows the structural assembly 1 according to FIGS. 1 to 14 with an additional interface element in the form of a top tether strap 12R. The top tether strap 12R is formed by a blank 132 of organosheet. The top tether strap 12R is configured and configured to be connected to and support a seatbelt. The blank 132 is connected to the planar element 10 in a materially integral manner, for example by means of injection molding and / or by contacting and heating the planar element 10 and the blank 132.In the case of a vehicle crash, in particular a front crash, large forces can act on a safety item connected to the top tether strap 12R. In this case, there is the risk that the seat belt slips laterally, as a result of which a risk of injury to a passenger can be increased. In order to prevent such a slipping, the structural assembly 1 is (optionally) provided with predetermined breaking points. The predetermined breaking points are designed in the form of predetermined breaking lines 14. The break lines 14 are parallel and spaced apart and adjacent the upper end edge 16C. With respect to the upper end edge 16C, the break lines 14 are substantially perpendicular. The predetermined breaking lines 14 are designed, for example, in the form of ribs or notches and / or material weakenings. In the present case, the predetermined breaking lines 14 are formed by weakenings in the form of notches in the stiffening surface 11P injection-molded onto the planar element 10. Alternatively or additionally, the surface element 10 can also be provided with weakenings. The weakenings are designed and configured to cause a material failure at a predetermined location when an acting force exceeds a predetermined maximum force (e.g. in a so-called ADR pull).When the predetermined breaking lines 14 break, a recess is formed at the upper end edge 16C, into which the seat belt engages and by means of which it is prevented from laterally slipping. The seat belt is thus caught.The structural assembly 1 described with reference to FIGS. 1 to 19 is therefore designed as an organo-sheet-plastic hybrid component and therefore satisfies high stability requirements with a particularly low weight. By integrating a plurality of stiffening elements 11A- 11P and interface elements 12A- 12Q into the structural assembly 1, production is additionally particularly simple. This is because the number of connecting processes required can be significantly reduced in this way.The planar element 10 is produced from organosheet and thus from a thermoformable composite material. To produce the planar element 10, the organosheet is provided in planar form and thus as a planar material. In order to produce the surface element 10, a corresponding piece is cut or punched out of the surface of the organosheet. Alternatively, a corresponding piece of organosheet is already produced in this shape and no longer has to be cut to size.In a subsequent step, the blank from which the planar element 10 is to be produced is shaped. Since the organosheet is a thermoformable material, this can be effected in a simple manner by means of thermoforming, that is to say by heating the blank with subsequent mechanical deformation.The stiffening elements 11A- 11P and the interface elements 12A- 12Q (with the exception of the top tether strap 12R) are not produced in the present case from organic sheet metal. Instead, they consist of a plastic and are injection-molded onto the surface element 10 by means of plastic injection molding. The stiffening elements 11A- 11P and the interface elements 12A- 12Q are connected to the planar element 10 in a materially integral manner in this way. In order to simplify the production of the structural assembly 1 as much as possible, the shaping of the planar element 10 can be carried out in the same tool as the injection molding.Depending on the thermoplastic material of which the matrix of the organosheet embedding the fiber material piece consists, it may be advantageous to use the same plastic material by injection molding in order to form the stiffening elements 11A- 11P and the interface elements 12A- 12Q.During the injection molding, the injection molding material forming the reinforcing ribs 11D and the supporting ribs 110 extending therefrom is injected into the injection mold at various locations. In this case, the injection molding material flows (depending on the arrangement of the injection points) from the section of the injection molding tool forming the supporting rib 110 into the section forming the stiffening rib 11D or vice versa. Since the support ribs 110 are formed with open ends 111, no two fronts of injection-molding material flows meet. In contrast to this, when crossing points of stiffening ribs 11A-11D, 11F-11H, 11N are produced, a plurality of such fronts can meet one another. The fronts enter into a cohesive connection. In the region of this connection, however, the corresponding reinforcing rib 11A- 11D, 11F- 11H, 11N can possibly be less highly loaded than in regions which are formed by a single injection-molding material stream (in particular, the connection can tear open under a tensile load). The reinforcing ribs 11D provided with supporting ribs 110 therefore have a particularly high stability against a tensile load.During injection molding, insert parts (such as the headrest bow 126) are injection molded by means of insert technology with the production of a positive connection with the planar element 10.Incomplete consolidation of a region (e.g. in the region of the end edge 106) of the planar element 10 can be effected by injection molding (or generally by heating). The surface element 10 is then not fully pressed in the region in order to obtain the incomplete consolidation.List of reference characters1 Structural assembly 10 Planar element 100 Receptacle 101 Edge 102 Inner edge 103 Opening 104 Depression 105 Flange 106 End edge 107 Cutout 108 Tab 109 Not fully consolidated region 11A Vertical stiffening rib 11B Horizontal stiffening rib 11C Right-inclined stiffening rib 11D Left-inclined stiffening rib 11E Edge reinforcement 11F Longitudinal rib 11G Connecting rib 11H Stiffening rib 11J End edge surround 11K Edge reinforcement (tapered region) 11L Stiffening insert 11M Stiffening frame 11N Stiffening rib 11P Stiffening surface 110 Supporting rib 111 Open end 112 Slope 113 Base 12A Screw boss 12B Positioning pin 12C Pivot joint bearing 12D Headrest holder 12E Lock holder 12F Cable clamp 12G cable holder 12H first cable guide 12J second cable guide 12K screw connection 12L screw connection 12M piping channel 12N adhesive channel 12P holder 12Q latching dome 12R top tether bracket 120 base 121 supporting rib 122 threaded bushing 123 receptacle 124 undercut 125A first receptacle 125B second receptacle 125C third receptacle 126 head restraint bracket 127 guide track 128 metal insert 129A screw insert (threaded bolt) 129B screw insert (threaded bushing) 130A, 130B foot 131 injection molding material 132 blank 133 piping hook 14 predetermined breaking line 16A, 16b side edge 16C upper end edge 16D lower end edge 2 armrest support 20 screw 21 tab 3 lock 30 lock mechanism 31 button 310 guide pin 32 screw 33 securing nut 4 cross tube 40 sheet metal clamp 41 screw 42 support arm 5 rod 50 depression A cutout B1 tapered region B2 non-tapered region B3 cross region B4 parallel region B5 transition region K crossing point S pivot axis

Claims

Structural assembly (1) for a vehicle seat backrest, having - a planar element (10) which is designed and configured to form at least part of a rear wall of the vehicle seat backrest and / or to close a cutout for loading through in the passenger seat backrest, and - at least one interface element (12A-12R) which is designed and configured for connection to a further component (2-5) of the vehicle seat backrest, characterized in that the planar element (10) is produced from a thermoformable composite material and is connected in a materially integral manner to at least part of the interface element (12M, 12N), wherein the at least one interface element (12M, 12N) is designed as a channel, which - is designed as a piping channel and comprises at least one piping hook (133) for holding a cladding as a further component or - is designed as a cable channel for receiving a cable, wherein at least one baffle is provided for the cable.Structural assembly (1) according to Claim 1, characterized in that the composite material is designed as a composite composed of a thermoplastic plastics matrix and a fibre material piece embedded therein, in particular as an organosheet.Structural assembly (1) according to Claim 2, characterized in that the fibre material piece of the planar element (10) is designed as a woven fabric, as a laid scrim, as a balanced woven fabric and / or as a sheared woven fabric.Structural assembly (1) according to Claim 2 or 3, characterized in that the fibre material piece of the planar element (10) is not fully consolidated in a region of the materially bonded connection to the interface element.Structural assembly (1) according to one of Claims 2 to 4, characterized in that the fibre material piece has at least one cut-out.Structural assembly (1) according to one of the preceding claims, characterized in that the interface element (12A-12R) is produced from a different material than the planar element (10), in particular is produced from the same material as a thermoplastic matrix of the composite material of the planar element (10).Structural assembly (1) according to one of the preceding claims, characterized in that the planar element (10) is designed in the form of a trough and / or forms a receptacle (100) which provides at least part of a pivot joint bearing (12C) for connecting the structural assembly (1) to the vehicle seat backrest.Structural assembly (1) according to one of the preceding claims, characterized in that the planar element (10) and / or the interface element has at least one predetermined breaking point (14).Structural assembly (1) according to one of the preceding claims, characterized in that the at least one interface element (12J, 12M, 12N) is arranged in the region of an edge (101) of the planar element (10) which has a C- or Z-shaped cross section.Structural assembly (1) according to one of the preceding claims, characterized in that at least one further interface element (12A, 12K, 12L) is provided and is designed as a screw dome, with which the further component (2) can be screwed, and / or at least one further interface element (12C) is provided and is designed as a pivot joint bearing for the pivotable connection of the structural assembly (1) to the vehicle seat backrest or for the pivotable connection of an armrest.Structural assembly (1) according to one of the preceding claims, characterized in that at least one further interface element (12D, 12E, 12K, 12L, 12P, 12R) comprises an insert part (126, 128, 129A, 129B, 5) which is connected in a positively locking manner to the planar element (10) and is in particular produced from a metal.Structural assembly (1) according to Claim 11, characterized in that the insert part (5) has at least one opening (50) and / or depression, into which a partial region of the planar element (10) is impressed.Structural assembly (1) according to either of Claims 11 and 12, characterized in that the at least one further interface element (12D) is designed and configured for connection to a headrest, and in that the insert part (126) is a headrest bow which is designed and configured to receive and support a headrest rod of the headrest.Structural assembly (1) according to either of Claims 11 and 12, characterized in that the insert part (129A, 129B) is designed as a threaded insert which is arranged in particular in an opening (103) in the planar element and with which the further component (2) can be screwed.Structural assembly (1) according to one of the preceding claims, characterized in that at least one further interface element (12E) is designed and configured for connection to an actuating element (31), which can be actuated for locking and / or unlocking a lock (3), wherein the interface element (12E) comprises at least one guide track (127) which is designed and configured to guide the actuating element (31) during actuation.Structural assembly (1) according to one of the preceding claims, characterized in that at least one further interface element (12R) is designed as a top tether bracket.Structural assembly (1) according to one of the preceding claims, characterized in that at least one further interface element has an elastic spring element which is designed and configured to cushion an adjacent further component of the vehicle seat backrest during a relative movement between the structural assembly and the adjacent further component of the vehicle seat backrest.Structural assembly (1) according to one of the preceding claims, characterized in that at least one stiffening element (11A-11P) is provided, which is designed and configured to increase the stiffness of the planar element (10).Structural assembly (1) according to claim 18, characterised in that the surface element (10) produced from a thermoformable composite material is connected in a materially integral manner to at least a part of the stiffening element (11A-11P).Structural assembly (1) according to either of Claims 18 and 19, characterized in that the composite material is designed as a composite composed of a thermoplastic plastics matrix and a fibre material piece embedded therein, in particular as an organosheet, and the fibre material piece of the planar element (10) is not fully consolidated in a region of the materially bonded connection to the stiffening element (11J, 11N).Structural assembly (1) according to one of Claims 18 to 20, characterized in that the stiffening element (11A-11P) is produced from a different material than the planar element (10), in particular is produced from the same material as a thermoplastic matrix of the composite material of the planar element (10).Structural assembly (1) according to one of Claims 18 to 21, characterized in that the stiffening element (11P) has at least one predetermined breaking point.Structural assembly (1) according to one of Claims 18 to 22, characterized in that the at least one stiffening element (11A-11D, 11F-11H, 11N) is designed as an elongate stiffening rib which extends along the planar element (10) and projects therefrom.Structural assembly (1) according to claim 23, characterised in that the stiffening rib (11A-11D, 11F-11H, 11N) has at least in sections a rectilinear course along the surface element (10) and / or at least one supporting rib (110) is provided which projects perpendicularly from the stiffening rib (11D).Structural assembly (1) according to one of Claims 23 or 24, characterized in that the reinforcing rib (11A-11D, 11F-11H, 11N) is of S-, C-, L- or T-shaped design in cross section and / or projects at an angle from the planar element (10) and / or the supporting rib (110) has an open end (111).Structural assembly (1) for a vehicle seat backrest, having - a planar element (10) which is designed and configured to form at least part of a rear wall of the vehicle seat backrest and / or to close a cutout for loading through in the vehicle seat backrest, and - at least one stiffening element (11A-11P) which is designed and configured to increase the stiffness of the planar element (10), and / or at least one interface element (12A-12R) which is designed and configured to be connected to a further component (2-5) of the vehicle seat backrest, characterized in that the planar element (10) is produced from a thermoformable composite material and is connected to at least part of the stiffening element (11A-11P) and / or of the interface element (12A-12R) in a materially integral manner, wherein the at least one interface element (12E) is designed and configured for connection to an actuating element (31) which is actuatable for locking and / or unlocking a lock (3), wherein the interface element (12E) comprises at least one guide track (127) which is designed and configured to guide the actuating element (31) during actuation.Vehicle seat for a motor vehicle, characterized bya backrest having a structural assembly (1) according to one of the preceding claims.Method for producing a structural assembly (1) for a vehicle seat backrest, having the following steps: - providing a surface element (10) which is designed and configured to form at least part of a rear wall of the vehicle seat backrest and / or to close a cutout for loading in the passenger seat backrest, and - providing at least one interface element (12A-12R) which is designed and configured for connection to a further component (2-5) of the structural assembly, characterized in that - the surface element (10) is produced from a thermoformable composite material and - the surface element (10) is connected to at least part of the interface element (12A-12R) in a materially bonded manner, wherein the at least one interface element (12M, 12N) is designed as a channel, which - is designed as a piping channel and comprises at least one piping hook (133) for holding a cladding as a further component or - is designed as a cable channel for receiving a cable, wherein at least one baffle is provided for the cable.Method according to claim 28, characterised in that the interface element (12A-12R) is injection-moulded onto the surface element (10) by means of injection moulding, in particular by means of two-component injection moulding.Method according to one of claims 28 or 29, characterised in that the composite material is formed as a composite of a thermoplastic plastic matrix and a fibre material piece embedded therein, wherein at least one opening (103) is formed in the surface element (10) and fibres of the fibre material piece are displaced substantially non-destructively in order to form the opening (103).Method according to one of Claims 28 to 30, characterized bycomprising at least one stiffening element (11A-11P) which is designed and configured to increase the stiffness of the planar element (10).Method according to claim 31, characterised in that the surface element (10) is connected to at least a part of the stiffening element (11A-11P) in a materially integral manner.Method according to either of Claims 31 and 32, characterized in that the stiffening element (11A-11P) is injection-moulded onto the planar element (10) by means of injection moulding, in particular by means of two-component injection moulding.

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