Arrangement of a rear-seat system on a floor structure of a passenger car

Abstract

The invention relates to an arrangement of a rear-seat system (1) on a floor structure (2) of a passenger car, having a front transverse element (6), on which respective front fastening points (16) for a seat frame (17) of the rear-seat system (1) are arranged, and having a rear transverse element (7) arranged behind the front transverse element (6) in the longitudinal direction of the vehicle, on which respective rear fastening points (18) for the seat frame (17) of the rear-seat system (1) are arranged. The rear transverse element (7) is in the form of a tailor-welded blank component (19) which has at least two mutually different wall thicknesses (29, 32) and at least two mutually different material properties (34, 37).

Description

[0001] Arrangement of a rear seat system on a floor structure of a passenger car

[0002] The invention relates to an arrangement of a rear seat system on a floor structure of a passenger car according to the preamble of patent claim 1.

[0003] Such rear seat systems and their arrangement on a floor structure in passenger cars are already well known from the general state of the art. Rear seat systems with folding backrests can be used, which can be locked by means of a locking device acting on the lower area of ​​the backrest. Such rear seat systems or their locking device can be referred to in particular as low-lock systems. Alternatively, rear seat systems with folding backrests can be used, which can be locked in the upper area of ​​the backrest between the backrest and a locking device acting on the vehicle body. This can be referred to in particular as high-lock systems. Accordingly, the backrest can be at least indirectly fixed to the vehicle body.

[0004] The object of the present invention is to provide an arrangement of a rear seat system on a floor structure of a passenger car so that the weight of the passenger car can be kept particularly low.

[0005] This object is achieved according to the invention by an arrangement of a rear seat system on a floor structure of a passenger car with the features of patent claim 1. Advantageous embodiments with favorable further developments of the invention are the subject of the dependent patent claims.

[0006] The invention relates to an arrangement of a rear seat system on a floor structure of a passenger car.

[0007] In particular, the rear seat system is arranged in an interior of the passenger car. The rear seat system is arranged in a rear partial area of ​​the interior relative to a longitudinal direction of the passenger car, wherein this rear partial area can in particular be referred to as the rear. The rear seat system can therefore be understood in particular as a second row of seats. Thus, in the interior in the vehicle longitudinal direction in front of the second row of seats, for example, a first row of seats is arranged, which has at least one seat system or several seat systems. The front row of seats is arranged in the front partial area of ​​the interior. The rear seat system preferably has several seats, each of which is intended for sitting one person.

[0008] The floor structure is preferably part of a body, which can in particular be referred to as a body structure. The body is preferably designed as a self-supporting body.

[0009] The floor structure has at least one front cross element, which is designed in particular as a front cross element on the bodyshell side. The front cross element is arranged, for example, in the region of a heel plate, in the region of which a vehicle floor running in a front region of the interior in the vehicle longitudinal direction preferably rises upwards in the vehicle vertical direction, for example at the level of the rear seat system. Respective front fastening points for a seat frame of the rear seat system are arranged on the front cross element in order to fix this in particular on the bodyshell side. In other words, the front cross element has a plurality of front fastening points via which or on which the seat frame of the rear seat system is to be held or is held.

[0010] The floor structure further comprises a rear cross member arranged behind the front cross member in the vehicle's longitudinal direction. This means that the rear cross member extends at least partially, in particular predominantly or completely, further rearward in the vehicle's longitudinal direction than the front cross member. Rear fastening points for the seat frame of the rear seat system, which are different from the front fastening points, are arranged on the rear cross member, in particular for securing the seat frame to the bodyshell. In other words, the rear cross member has a plurality of rear fastening points, via which or on which the seat frame of the rear seat system is to be held or is held.

[0011] In order to keep the weight of the passenger car, in particular of the floor structure, particularly low, the invention provides for the rear cross member to be designed as a tailor-welded blank component. In other words, the rear cross member is or will be manufactured using a tailor-welded blank (TWB). The tailor-welded blank component can be understood in particular as a sheet metal component, which can also be referred to as a tailored blank. The rear cross member or the tailor-welded blank component has at least two different wall thicknesses and at least two different material grades.This means that the rear cross member or the tailor-welded blank component has at least a first wall thickness and at least one second wall thickness different from the first wall thickness, as well as at least one first material grade and at least one second material grade different from the first material grade. In other words, the rear cross member has different wall thicknesses and different material grades in different length ranges. Thus, the rear cross member can have a first wall thickness and a first material grade in a first of the length ranges and the second wall thickness and the second material grade in a further length range, in particular different from the first length range.In other words, the rear cross member is designed as a sheet metal component to which the rear seat system is or will be attached via the rear attachment points, for example, by screwing. The sheet metal component is designed as a laser-cut blank with different sheet thicknesses and grades. In particular, the sheet metal component consists of the laser-cut blank or the tailor-welded blank component.

[0012] A tailor-welded blank component can be understood as individually welded sheet metal blanks, particularly using the tailor-welded blank process, with the welding being performed, for example, as a butt joint using laser welding. Different wall thicknesses can be understood in particular as different material thicknesses. Different material grades can be understood in particular as different material grades, in particular different material configurations, and / or different material types, for example, different steel grades.

[0013] The invention is based in particular on the following findings and considerations: The rear seat system, in particular referred to as a rear seat, can be mounted in the design referred to as high-lock to body structures, in particular to the front and rear cross members, for example using screws. This can be referred to in particular as a high-lock rear seat system. With a high-lock attachment of the second row of seats (high-lock), body-fixed screw points and / or nuts can be implemented with additional components. Alternatively or additionally, these can be stiffened using so-called bulkhead plates. This can make it possible to distribute operating loads along designated load paths in the body structure and to create the highest possible connection rigidity.

[0014] In contrast, when using a so-called low-lock seat, i.e. when the rear seat system is designed as a low-lock seat, more load or a particularly high load can be introduced into the body through the rear seat system than when using a high-lock seat. Seat attachment points in the body can experience higher loads in this case. Because the rear cross member is designed as a tailored blank component, the rear cross member can be designed as a single piece despite the different wall thicknesses and different material qualities, i.e. it can remain a single piece, so to speak. Due to the different wall thicknesses and / or the different material qualities, the rear cross member can be reinforced locally, in particular only where necessary. This means that no additional reinforcing components, bulkheads, brackets or the like are necessary.This can lead to a reduction in the weight of the passenger car, particularly the floor structure. Furthermore, the manufacturing effort for the passenger car can be kept particularly low. This can also lead to cost reductions. In particular, the rear cross member, designed as a tailor-welded blank component, can be used to connect the rear seat system, which is designed as a low-lock seat. Overall, it is clear that the body structure is designed to accommodate the second row of seats.

[0015] In a further embodiment, it is provided that the rear cross element has the first wall thickness and the first material quality in the first length range, in which at least one of the rear fastening points is arranged, and in the second length range, in which at least one of the rear fastening points, i.e. at least one other of the rear fastening points is arranged. This means that the rear cross element has the same wall thickness in the first and second length ranges, i.e. in particular an identical wall thickness value, and that the rear cross element has the same material quality in the first and second length ranges. In other words, the wall thickness is the same in the first and second length ranges and the material quality is the same in the first and second length ranges.Thus, in particular, the wall thickness values ​​of the wall thicknesses in the first and second length ranges are identical. The term "identical material grades" can be understood, in particular, to mean that the first and second length ranges are made of the same material, in particular with the same material specifications or the same material grade. Thus, those length ranges in which the rear attachment points are located can be dimensioned particularly thickly in the same way, allowing the rear seat system to be connected particularly securely to the floor structure. For example, the length ranges are spaced apart from one another, particularly in the transverse direction of the vehicle.

[0016] In a further embodiment, it is provided that the first and second length ranges are formed from one, in particular respective, dual-phase steel. In other words, the first length range is formed from a first material and the second length range is formed from a second material, wherein the first material is a dual-phase steel and the second material is a dual-phase steel. The material quality of the first and second length ranges can therefore be dual-phase steel, i.e. steel in dual-phase steel quality. Dual-phase steel can be understood in particular as steel whose microstructure has a ferritic (soft) matrix in which an at least predominantly martensitic (strength-enhancing) second phase is embedded, in particular in island form, at grain boundaries. The proportion of martensite is, for example, between 10 and 40 percent.Because the longitudinal sections are made of dual-phase steel, the rear cross member can be designed with exceptional stability at the attachment points. This significantly increases the mechanical load-bearing capacity of the rear cross member in the area of ​​the attachment points. This allows the rear seat system to be connected particularly securely to the floor structure.

[0017] In a further embodiment, it is provided that the rear cross element has at least one third longitudinal region extending, in particular in the transverse direction of the passenger car, between the first and the second longitudinal region. In other words, the third longitudinal region is arranged, in particular in the transverse direction of the vehicle, between the first and the second longitudinal region. This means that the first and the second longitudinal region are connected to one another via the third longitudinal region, for example at least indirectly or directly. In the third longitudinal region, the rear cross element has a second wall thickness that is different from the first wall thickness and a second material quality that is different from the first material quality. This means that a material of the third longitudinal region has the second wall thickness and the second material quality.In other words, the third length range has a different wall thickness and a different material quality relative to the first and second length ranges. The fact that the second wall thickness is different from the first wall thickness can be understood in particular to mean that a respective wall thickness value of the respective wall thickness in the respective length range is different in the third length range than in the first and second length ranges. The fact that the second material quality is different from the first material quality can be understood in particular to mean that the first and second length ranges are formed from a different material, in particular with a different material specification or material quality, than the third length range. The second wall thickness is preferably smaller than the first wall thickness.Thus, the rear cross member can be designed to be particularly stable in the area of ​​the fastening points, i.e., in the first and second longitudinal regions, and the wall thickness can be kept particularly low in the third longitudinal region, thereby keeping the weight of the rear cross member particularly low. For example, the third longitudinal region is free of fastening points for attaching the rear seat system. This means that the third longitudinal region preferably does not have a fastening point via which the seat frame of the rear seat system can be or is attached.

[0018] In the area of ​​the rear fastening points, i.e. in the area of ​​a seat connection for the rear seat system, a higher or particularly high sheet thickness, for example 2.2 mm, may be necessary as the first wall thickness than in other areas of the rear cross member. This may be necessary, for example, to ensure that a weld nut is not torn out of the sheet metal during static belt tension and / or in the event of a crash, so that the weld nut can be attached particularly securely. In order to keep the weight of the passenger car particularly low and / or to keep the manufacturing effort, in particular manufacturing costs, of the passenger car particularly low, a lower sheet thickness, for example 1.4 mm, in the form of the second wall thickness, can be used in non-critical areas, for example in the form of the third length range.

[0019] In a further embodiment, the third length range is formed from a micro-alloyed steel. Micro-alloyed steel can be understood, in particular, as an unalloyed steel to which, for example, particularly small amounts of vanadium and / or niobium and / or titanium or the like are added, particularly as a micro-alloying element. This embodiment is based, in particular, on the following findings and considerations:

[0020] In order to make the rear cross member particularly stable in the area of ​​the rear attachment points, i.e. in the area of ​​a seat connection, it may be necessary to use at least one dual-phase steel for this purpose, i.e. in the first and second length ranges. This can be demonstrated, for example, by simulating static belt tension and a high-speed rear-end crash and / or a high-speed front-end crash. However, due to complex component geometry, it may not be possible or particularly difficult to manufacture the entire rear cross member in this quality, i.e. as dual-phase steel. Micro-alloyed steel can therefore be used, particularly in areas with a particularly high degree of deformation. The third length range, for example, is therefore a length range with a high or particularly high degree of deformation.On the one hand, the weight of the passenger car can be kept particularly low and, on the other hand, the passenger car, in particular its floor structure, can be manufactured with particularly little effort.

[0021] In a further embodiment, it is provided that a respective edge region adjoins the first and the second longitudinal region outwards in the transverse direction of the vehicle. In other words, the rear transverse element has at least two edge regions, wherein a first of the edge regions adjoins the first longitudinal region outwards in the transverse direction of the vehicle, in particular at least indirectly or directly, and the second edge region adjoins the second longitudinal region outwards in the transverse direction of the vehicle. In other words, the first edge region is arranged further outwards in the transverse direction of the vehicle than the first longitudinal region and the second edge region is arranged further outwards in the transverse direction of the vehicle than the second longitudinal region.In each edge region, the rear cross member has a third wall thickness different from the first wall thickness and a third material grade different from the first material grade. In other words, the respective edge region has a different wall thickness and a different material grade relative to the first and second length regions. The third wall thickness is preferably less than the first wall thickness. Thus, in a non-critical area of ​​the rear cross member in the form of the respective edge region, the corresponding wall thickness can be kept particularly low, thereby keeping the weight of the passenger vehicle or the floor structure particularly low.

[0022] Preferably, the second wall thickness and the third wall thickness are identical. This means that the respective wall thickness value of the respective wall thickness is identical in the third length region and in the edge regions. Alternatively or additionally, the second material grade and the third material grade are identical. In other words, the third length region and the edge regions are formed from the same material, in particular with the same material specification or material grade. This allows the manufacturing costs of the passenger car to be kept particularly low.

[0023] In a further embodiment, the edge regions are formed from a micro-alloyed steel. Thus, analogous to the third length region, lower-grade steel can be used for the edge regions than in the first and second length regions. This allows the rear cross member to be manufactured with particularly low effort, especially if the rear cross member has a particularly high degree of deformation in the edge regions.

[0024] In a further embodiment, it is provided that the rear cross element is held via the edge regions to a respective body component of the floor structure, for example designed as a respective longitudinal member. In other words, the rear cross element is connected via the first edge region to a first body component, in particular directly, and via the second edge region the rear cross element is connected to a second body component of the floor structure, in particular designed separately from the first body component, for example at least indirectly or directly. The respective body component is designed, for example, as a respective longitudinal member. As a result, the connection of the rear cross element to the body components can be particularly inexpensive.

[0025] In a further embodiment, it is provided that a backrest of the rear seat system can be folded about a pivot axis running in a lower region and can be locked by means of a locking device acting in the lower region of the backrest. The lower region can be understood in particular as a lower region related to the vehicle's vertical direction. A locking device of this type acting in the lower region of the backrest (English: low-lock) has the particular advantage that no locking device needs to be provided between the backrest and the body of the passenger car in the upper region of the backrest, but that the entire fixation of the foldable backrest takes place, for example, via the respective seat fittings and subsequently via the seat frame. This allows the rear seat system to be attached particularly advantageously.In particular, no additional fastenings are required to lock the folding backrest. Furthermore, such a rear seat system, with the locking device engaging the lower area of ​​the backrest, can allow access to a receiving space in which, for example, components of an electrical energy storage system for the electric drive of the passenger car, such as power electronics components, are located.

[0026] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or on their own.

[0027] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show:

[0028] Fig. 1 is a schematic partial perspective view of an arrangement according to the invention of a rear seat system on a floor structure of a passenger car; and

[0029] Fig. 2 is a schematic partial perspective view of the

[0030] Floor structure of the passenger car of an arrangement according to the invention; and

[0031] Fig. 3 is a schematic perspective view of a rear cross member of an arrangement according to the invention.

[0032] In the figures, identical or functionally equivalent elements are provided with the same reference numerals. Fig. 1 shows, in a schematic and perspective partial view, an arrangement of a rear seat system 1 of a floor structure 2 of a passenger car body. This floor structure 2 can be seen in Fig. 2 in a schematic and perspective partial view with the rear seat system 1 omitted. Thus, the rear seat system 1 is not shown in Fig. 2.

[0033] A joint view of Fig. 1 and Fig. 2 reveals that the floor structure 2 in the exemplary embodiment comprises respective lateral longitudinal members 3, which extend in the vehicle's longitudinal direction 4 from the front, not visible, wheel arches to the rear wheel arches 5. A front transverse element 6, in particular in the form of a cross member, extends between the lateral longitudinal members 3. The front transverse element 6 is designed in the exemplary embodiment as a heel element, in particular as a heel plate. For example, a front vehicle floor is arranged on the front transverse element 6, which extends forward in the vehicle's longitudinal direction 4, for example, to a lower end of a front bulkhead or a cross member arranged in this region. In particular, the front vehicle floor ends rearward in the vehicle's longitudinal direction 4 at the front transverse element 6.The front vehicle floor is formed, for example, at least partially by a storage housing for an energy storage device, in particular an electrical one. Vehicle seats of a front vehicle seat row, for example, are arranged above this front vehicle floor. The rear seat system 1 is a rear vehicle seat row arranged behind the front seat row in the vehicle's longitudinal direction 4.

[0034] A rear cross member 7 of the floor structure 2 is arranged behind the front cross member 6 in the vehicle's longitudinal direction 4. The rear cross member 7 is, for example, part of a transverse structure 8, which is composed, for example, of several sheet metal components, one of these sheet metal components being, for example, the rear cross member 7. The rear cross member 7 extends, for example, at the front between the two longitudinal members 3 with respect to the vehicle's longitudinal direction 4, and at the rear between lateral longitudinal members 9 of a rear section 10 of the body with respect to the vehicle's longitudinal direction 4. The rear section 10, in particular the lateral longitudinal members 9, adjoin the rear ends of the lateral longitudinal members 3, for example, towards the rear in the vehicle's longitudinal direction 4.Furthermore, a further cross member 12 and a rear floor 13 can be seen on the rear section 10, extending in the vehicle longitudinal direction 4 behind the cross member 7 and in particular parallel to the latter in the vehicle transverse direction 11.

[0035] In the exemplary embodiment, the front cross element 6 and the rear cross structure 8 delimit a receiving space 30 in which components of the energy storage device for the electric drive of the passenger car, for example power electronics components, are accommodated.

[0036] A combined view of Figs. 1 and 2 also shows that, in the exemplary embodiment, the front transverse element 6 comprises respective support elements 15 extending upwards in the vehicle's vertical direction 14, to which respective fastening points 16 are provided for fastening a seat frame 17 of the rear seat system 1. In the present case, four support elements 15 and thus also four front fastening points 16 are provided for the rear seat system 1 or its seat frame 17.

[0037] Rear fastening points 18 are arranged on the rear cross element 7 and are provided for the seat frame 17 of the rear seat system 1. This means that the rear cross element 7 comprises the rear fastening points 18, via which the seat frame 17 of the rear seat system 1 is to be held or is held. The rear seat system 1 can be fixed on top via the fastening points 16, 18. In the exemplary embodiment, the front and rear cross elements 6, 7 are spaced apart from one another in the vehicle longitudinal direction 4. The rear fastening points 18 are illustrated in Fig. 3, in which the rear cross element 7 is shown in a schematic perspective view. For example, the respective cross element 6, 7 is screwed to the seat frame 17, in particular directly, at the respective fastening point 16, 18.

[0038] In order to be able to keep the weight of the passenger car, in particular of the floor structure 2, particularly low and in particular to be able to keep the manufacturing costs of the passenger car or of the floor structure 2 particularly low, it is provided that the rear cross element 7 is designed as a tailor-welded blank component 19 which has at least two mutually different wall thicknesses 29, 31 and 29, 32 and at least two mutually different material qualities 34, 36 and 34, 37. In the exemplary embodiment, the rear cross element 7 has at least three longitudinal regions 20, 21, 22. These longitudinal regions 20, 21, 22 can be understood in particular as longitudinal regions 20, 21, 22 extending in the vehicle transverse direction 11.Furthermore, the rear cross member 7 in the exemplary embodiment has two edge regions 23, 24, wherein the edge regions 23, 24 can be understood in particular as a fourth and a fifth longitudinal region of the rear cross member 7. Furthermore, the edge regions 23, 24 can be understood in particular as edge regions 23, 24 of the rear cross member 7 related to the vehicle transverse direction 11. In the exemplary embodiment, it is provided that the rear cross member 7 is held via the edge regions 23, 24 on a respective body component 3a of the floor structure 2 in the form of the respective longitudinal member 3. In particular, the longitudinal regions 20, 21, 22 and the edge regions 23, 24 are formed by the tailor-welded blank component 19. At least one of the rear fastening points 18, for example exactly one rear fastening point 18, is arranged in a first of the longitudinal regions 20.In a second of the longitudinal regions 21, at least one other of the fastening points 18 is arranged, which can in particular be referred to as the second of the fastening points 18. In the exemplary embodiment, two of the rear fastening points 18 are arranged in the second longitudinal region 21, which can in particular be referred to as the second and third fastening points 18. The third longitudinal region 22 extends between the first and the second longitudinal region 20, 21. The first and the third longitudinal region 20, 22 are connected to one another via a first transition region 25, in particular directly, which is designed, for example, as a laser weld seam. The second and the third longitudinal region 22, 23 are connected to one another via a second transition region 26, in particular directly, which is designed, for example, as a laser weld seam.The first longitudinal region 20 and a first of the edge regions 23 are connected to one another, in particular directly, via a third transition region 27, which is designed, for example, as a laser weld seam. The second longitudinal region 21 and the second edge region 24 are connected to one another, in particular directly, via a fourth transition region 28, which is designed, for example, as a laser weld seam. The respective laser weld seam can in particular be referred to as a laser seam. The rear transverse element 7 can therefore also be referred to as a laser plate.

[0039] In the first length region 20 and in the second length region 21, the rear cross element 7 has, for example, a first wall thickness 29, which is, for example, 2.2 millimeters. In the exemplary embodiment, the rear cross element 7 has, in the third length region 22, a second wall thickness 31 which is different from the first wall thickness 29 and, in particular, lesser than the first wall thickness 29 and, for example, amounts to 1.4 mm. Furthermore, in the exemplary embodiment, the rear cross element 7 has, in each edge region 23, 24, a third wall thickness 32 which is different from the first wall thickness 29 and, in particular, lesser than the first wall thickness 29. The second wall thickness 32 is, for example, 1.4 mm. Thus, it can be provided that the second wall thickness 31 and the third wall thickness 32 are the same. In other words, the edge regions 23, 24 each have the second wall thickness 31.However, it is of course alternatively possible for the second and third wall thicknesses 31, 32 to be different from one another. Due to the different wall thicknesses 29, 31, 32, the rear cross member 7 can be ideally adapted locally to the mechanical loads acting on it, for example, in the event of an accident. This can be achieved in a particularly weight-saving manner through local material savings.

[0040] Furthermore, in the exemplary embodiment, the rear cross element 7 has a first material grade 34 in the first length region 20 and in the second length region 21. In the third length region 22, the rear cross element 7 has, for example, a second material grade 36 that differs from the first material grade 34. Furthermore, the rear cross element 7 here has, in the respective edge regions 23, 24, a third material grade 37 that differs from the first material grade 34. Preferably, the second and third material grades 36, 37 are the same. In other words, the edge regions 23, 24 have the second material grade 36. However, it can of course alternatively be provided that the second and third material grades 36, 37 are different from one another.

[0041] In the exemplary embodiment, it is further provided that the first and second length regions 20, 21 are formed from a dual-phase steel 39. Thus, the first material grade 34 is formed according to the dual-phase steel 39. Furthermore, in the exemplary embodiment, the third length region 22 and the edge regions 23, 24 are formed from a, in particular respective, micro-alloyed steel 40. Thus, the second material grade and the third material grade 36, 37 are formed according to the micro-alloyed steel 40. Thus, for example, it is provided that the first, second and third length ranges 20, 21, 22 are formed from steel, wherein the steel according to the first material grade 34 preferably has a higher yield strength than the steel according to the second material grade 36. In particular, the first and second length ranges 20, 21 are formed from steel with the first material grade 34 and the third length range 22 is formed from steel with the second material grade 36.Alternatively or additionally, the first and second longitudinal regions 20, 21 and the edge regions 23, 24 are formed, for example, from steel, wherein the steel according to the first material grade 34 preferably has a greater tensile strength, for example at least 1.5 times greater tensile strength, than the steel according to the third material grade 37. By hardening, in particular work hardening, particularly positive properties can be achieved during forming by the dual-phase steel. In particular, the edge regions 23, 24 are formed from steel with the third material grade 37. In the present case, the tensile strength of the first material grade is, for example, at least 450 MPa and the tensile strength of the second material grade 36 and the third material grade 37 is, for example, at least 780 MPa. For example, the first and second longitudinal regions 20, 21 are formed from the steel CR440Y780T.For example, the third longitudinal region 22 and / or the edge regions 23, 24 are formed from CR380LA steel. In other words, the first material grade, for example, is 34 steel CR440Y780T, and the second and third material grades 36, 37 are, for example, CR380LA steel.

[0042] For example, it is provided that the edge regions 23, 24 have a higher degree of deformation than the first and second length regions 20, 21, in particular the third length region 22. This means that in order to produce the rear cross element 7, in particular from a tailor welded blank, the edge regions 23, 24 have to be formed or reshaped more extensively, i.e. more strongly, by means of forming than the first and second length regions 20, 21 and in particular the third length region 22. This means in particular that in order to produce the rear cross element 7, more forming steps have to be carried out or are carried out during the forming of the edge regions 23, 24 than in the first and second length regions 20, 21, and in particular in the third length region 22. The outer edge regions 23, 24 can therefore be a respective region 45 with a high or particularly high degree of deformation.This can be made possible by the third material grade of the edge regions 23, 24, and in particular by using CR380LA steel. As a result, the rear cross element 7 can be manufactured with particularly little effort in a particularly lightweight manner. The higher degree of deformation can be understood in particular to mean that a respective geometry, in particular surface geometry, of the respective edge region 23, 24 has more, in particular local, changes in direction and / or is more delicately designed than the first and second longitudinal regions 21, 22, and in particular the third longitudinal region 23. In the exemplary embodiment, it is provided that a backrest 41 of the rear seat system 1 can be folded about a pivot axis 43 running in a lower region 42 and can be locked by means of a locking device 44 engaging in the lower region 42 of the backrest 41.In other words, the locking of the backrest 41 or respective backrests 41 of the rear seating system 1 takes place, in particular exclusively, in the lower region 42. Thus, it is particularly provided that the locking device engages in the region of the pivot axis 43, i.e. at least in the vicinity, in particular in the immediate vicinity, of the pivot axis 43 for locking the backrest 41. The backrest 41 can have a plurality of backrest parts, each of which can be assigned to a respective seat of the rear seating system 1. Folding the backrest 41 can be understood in particular as pivoting the backrest 41, for example to at least one seat part 44 of the rear seating system 1, about the pivot axis 43.

[0043] The described arrangement thus enables the use of the rear seat system 1 designed as a low-lock seat. This means that a low-lock locking mechanism for the rear seat system 1 can be enabled. A low-lock rear seat can therefore be installed, whereby a bracket for a rear seat backrest lock is no longer screwed to the bodyshell, unlike with a high-lock seat, for example. The backrest and seat surface of the rear seat system 1 can be represented in one seat structure. By using the rear cross element 7, which is referred to in particular as a laser-cut blank and designed as a tailor-welded blank component 19, weight savings and savings in manufacturing costs can be made possible. In this case, for example, a connection of the backrest 41, which is referred to in particular as a rear seat backrest, in particular centrally, to a cross member arranged in the area of ​​a luggage compartment floor can be avoided.This cross member can in particular be referred to as a “front luggage compartment floor cross member.” Reinforcement of a center bearing for the backrest 41 can also be omitted. Furthermore, a connection of the backrest 41, in particular in an outer region relative to the vehicle transverse direction 11, to an additional component provided for reinforcing an outer backrest bearing can be avoided. This backrest bearing can in particular be referred to as an “outer backrest bearing.” Furthermore, a connection of the backrest 41, in particular in an outer region relative to the vehicle vertical direction 14, to an additional component provided for reinforcing an upper backrest bearing can be avoided. This backrest bearing can in particular be referred to as an “upper backrest bearing.” Provision can be made for a center automatic belt retractor, i.e. an automatic belt retractor provided for a center seat of the rear seating system 1, to be integrated into the rear seating system 1.This can lead to additional force introduction, whereby in the event of static belt tension and in the event of a rear-end crash or front-end crash, in particular a high-speed rear-end crash or high-speed front-end crash, particularly high forces can be introduced into the body via a seat structure of the rear seat system 1. However, the rear cross member 7 designed as a tailor-welded blank component 19 makes it possible to avoid additional parts such as bulkheads, reinforcements or the like. As a result of the integrated automatic belt mechanism, the two fastening points 18, for example, are provided in the second longitudinal region 21. The fact that two of the fastening points 18 are arranged in the second longitudinal region 21 can therefore be particularly useful for the middle automatic belt mechanism, in particular a seat-integrated middle automatic belt mechanism. Furthermore, when connecting the backrest 41 in the low-lock seat via weld nuts, particularly few screw points can be possible.This can result in a high force acting per screw point. The middle seat can cause additional stress. This load can be withstood by means of the rear cross member 7, particularly through its described design with regard to wall thicknesses 29, 31, 32 and material grades 34, 36, 37.

[0044] List of reference symbols

[0045] Rear seat system Floor structure Longitudinal member a Body component Vehicle longitudinal direction Wheel house Front cross member Rear cross member Cross structure Rear longitudinal member 0 Rear end 1 Vehicle transverse direction 2 Further cross member 3 Rear floor 4 Vehicle vertical direction 5 Support element 6 Front attachment points 7 Seat frame 8 Rear attachment points 9 Tailor Welded Blank component 0 First length range 1 Second length range 2 Third length range 3 First edge range 4 Second edge range 5 First transition area 6 Second transition area 7 Third transition area 8 Fourth transition area 9 First wall thickness 0 Accommodating space 1 Second wall thickness 2 Third wall thickness 4 First material grade Second material grade Third material grade Dual-phase steel Micro-alloyed steel Backrest Lower area Swivel axis Seat part area

Claims

Patent claims 1. Arrangement of a rear seat system (1) on a floor structure (2) of a passenger car, with a front cross element (6), on which respective front fastening points (16) for a seat frame (17) of the rear seat system (1) are arranged, and with a rear cross element (7) arranged behind the front cross element (7) in the vehicle longitudinal direction (4), on which respective rear fastening points (18) for the seat frame (17) of the rear seat system (1) are arranged, characterized in that the rear cross element (7) is designed as a tailor-welded blank component (19) which has at least two mutually different wall thicknesses (29, 32) and at least two mutually different material qualities (34, 37).

2. Arrangement according to claim 1, characterized in that the rear transverse element (7) has a first wall thickness (29) and a first material quality (34) in a first longitudinal region (20), in which at least one of the rear fastening points (18) is arranged, and in a second longitudinal region (21), in which at least one of the rear fastening points (18) is arranged.

3. Arrangement according to claim 2, characterized in that the first and second length regions (20, 21) are formed from a dual-phase steel (39).

4. Arrangement according to claim 2 or 3, characterized in that the rear transverse element (7) has a third longitudinal region (22) extending between the first and the second longitudinal region (20, 21), in which the rear transverse element (7) has a different wall thickness (29), in particular smaller than the first wall thickness (29), second wall thickness (31) and a second material quality (36) different from the first material quality (34).

5. Arrangement according to claim 4, characterized in that the third length region (31) is formed from a micro-alloyed steel (40).

6. Arrangement according to one of claims 2 to 5, characterized in that the first and the second longitudinal region (20, 21) are each adjoined outwards in the vehicle transverse direction (11) by a respective edge region (23, 24), in which the rear transverse element (7) in each case has a third wall thickness (32) which is different from the first wall thickness (29), in particular smaller than the first wall thickness (29), and a third material quality (37) which is different from the first material quality (34).

7. Arrangement according to claim 6 with reference to claim 4, characterized in that the second wall thickness (31) and the third wall thickness (32) are the same and / or the second material quality (36) and the third material quality (37) are the same.

8. Arrangement according to claim 6 or 7, characterized in that the edge regions (23, 24) are formed from a micro-alloyed steel (40).

9. Arrangement according to one of claims 6 to 8, characterized in that the rear transverse element (7) is held via the edge regions (23, 24) on a respective body component (3a) of the floor structure (2).

10. Arrangement according to one of the preceding claims, characterized in that a backrest (41) of the rear seat system (1) can be folded about a pivot axis (43) running in a lower region (42) and can be locked by means of a locking device acting in the lower region of the backrest (41).

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