Vehicle seat with two vehicle seat components

Abstract

Vehicle seat (1) comprising two vehicle seat components (3, 4, 5, 7) and a crossbar or cross tube (8, 9, 10), wherein each vehicle seat component (3, 4, 5, 7) has at least one deformation area (22) for at least partial plastic deformation, wherein each vehicle seat component (3, 4, 5, 7) has at least one receptacle (12) for components (8, 9, 10) to be attached as a reinforced, loaded area (20, 21) which is designed as a hardened area and adjoins or connects to the deformation area (22), wherein the hardened areas (20, 21) each have several welds (25, 26, 28), wherein the crossbar or cross tube (8, 9, 10) is received between the two vehicle seat components (3, 4, 5, 7) and is positioned and secured by the receptacle (12) of each of the two vehicle seat components (3, 4, 5, 7), wherein the welds are laser welds (25, 26, 28) and the steel material is hardened by local heating with complete or partial martensite formation, wherein intermediate line areas (29) of the hardened area (20, 21) between the welds (25, 26, 28) are formed without heat treatment and / or without martensite formation, where at least some of the several welds (25, 26, 28) are linear in form, wherein in each of the vehicle seat components several welds (26) encircle the receptacle (12) as a loaded area (12) or at least partially or locally surround it, and at least some welds (25, 26, 28) encircle the loaded area (12) to be reinforced with a greater curvature and run more straight or with less curvature outside the loaded area (12) to be reinforced to form a knot-like structure (27), wherein the deformation area (22) is arranged between two hardened areas (20, 21) and the deformation area (22) is designed as a buckling area or bulging area for buckling between the two hardened areas (20, 21) in the event of a deformation load, e.g. an accident, so that the vehicle seat components (3, 4, 5, 7) are selectively deformable in at least one deformation area (22) when subjected to high loads and in a crash,

Description

[0001] The invention relates to a vehicle seat with two vehicle seat components that are deformable when subjected to high forces, e.g. a vehicle accident.

[0002] DE 699 20 189 T2 shows a frame as an example of such a vehicle seat component. By selectively creating deformation zones, the energy generated in, for example, a rear-end collision can be absorbed in specific areas. According to DE 699 20 189 T2, the resistance of certain areas can be reduced by heat treatment, in particular tempering, in order to be specifically designed as deformation zones. Accordingly, the entire component can be converted into a martensitic structure by heating, after which the resistance of a deformation zone is weakened by the further heat treatment of tempering.

[0003] However, such large-area temperature treatments require considerable energy expenditure; furthermore, large-area martensite regions sometimes exhibit unfavorable mechanical properties.

[0004] German patent DE 10 2013 216 317 A1 describes a method for manufacturing a structural component of a vehicle seat in which the ductility of an area is increased by heat treatment, particularly in the case of iron-manganese steels or aluminum alloys. The heat-treated area thus exhibits improved reversible plastic deformability. The heat treatment can be carried out, in particular, using a laser, e.g., as a laser weld.

[0005] German patent DE 10 2011 101 700 A1 describes a tilt-adjustable seat structure consisting of a backrest and a seat cushion, which are adjustable to each other via a backrest adjuster. The components of the seat structure feature sections of laser-hardened material. This laser-hardened material is located in areas most vulnerable in a crash, where it is reinforced by laser welding to create hardened zones. This increases energy absorption in these areas, thus counteracting deformation or buckling. As a result, the energy absorption in the stressed areas can be increased by up to approximately 10%.

[0006] DE 10 2006 031 273 A1 discloses structures solidified by laser welding, which serve to direct deformation energy under external force, e.g., in the event of a crash, into deformation areas not treated by the laser beam. Linear, curved, or intersecting structures with patterns adapted to the respective application are provided.

[0007] DE 102011086650 A1 shows a structural component for a vehicle seat, with at least one laser-hardened region which is arranged in a section of the structural component that is subjected to high stress in at least one predetermined load case, extends through the section or borders the section in the structural component to reinforce the section against undesired deformation in the predetermined load case. It is further provided that the section is designed as an edge region of a recess or as an edge region of a hole in the structural component.

[0008] The invention is based on the objective of creating a vehicle seat and a method for its manufacture that enable a design with relatively little effort and have suitable mechanical properties, in particular a targeted deformability.

[0009] This problem is solved by a vehicle seat according to claim 1 and a method for its manufacture.

[0010] This creates a hardened area through heating, next to which a deformation area is arranged. A deformation area is formed between two hardened areas, so that the unhardened area can deform in a controlled manner between the hardened areas, e.g., by buckling or denting.

[0011] According to the invention, the hardened area is formed by several linear welds. In this case, more than one weld is formed in the sheet metal or steel plate of the vehicle seat component, and the welds are spaced apart from each other, or at least partially spaced apart.

[0012] Thus, the steel sheet material of the vehicle seat component can generally remain without any temperature treatment that fundamentally alters the structure or microstructure of the sheet material. The hardened areas are hardened by placing multiple welds, so that even the hardened areas are not completely through-hardened and exhibit martensite formation. It has been shown that a hardened area with, for example, multiple welds already possesses a high stiffness to remain undeformed in the event of deformation; a deformation zone remaining next to the hardened area, especially between two hardened areas, will buckle or deform in a controlled manner.

[0013] Thus, the hardened area can also have a non-martensitic basic structure or microstructure in its intermediate lines between the welds, e.g., in the known manner as pearlite, austenite, etc. The welds create a martensite formation in certain areas for hardening.

[0014] In this respect, the vehicle seat component and the method differ in particular from those of the aforementioned DE 10 2013 216 317 A1, in which such steels or aluminium alloys are used that the subsequent heat treatment results in higher ductility instead of hardening; the heat-treated area thus serves itself as a deformation area, instead of being adjacent to the deformation area or lying between two deformation areas as in the present invention.

[0015] The welds are produced by laser welding and can be formed quickly, reliably, and cost-effectively. Such laser welding processes are already established in steel processing, so adding laser welds requires little effort, in particular no significant additional equipment, and only a shorter process time, especially less time and energy than complete through-hardening, possibly with subsequent tempering, of a component. Since laser welding processes are often already used during assembly, the additional equipment costs are minimal.

[0016] The formation of a hardened area through multiple welds allows for considerable design freedom regarding hardening and orientation. For example, welds of varying thicknesses can be created by using a laser at different speeds. Furthermore, welds can be spaced differently and / or have different geometries.

[0017] Thus, the areas subject to stress, specifically the mountings for a further component, namely a crossbar or a cross tube, optionally also serving as a joint mount, are particularly reinforced by the welds. According to the invention, a knot-like structure is provided in which one or more welds partially surround or encircle such a stressed area or a stressed sub-area. In particular, several welds can be placed closer together around the stressed area and spaced further apart outside this stressed area.

[0018] This reveals that the bionic structure of a knot hole, or the pattern of wood fibers around a knot hole, can be replicated during the formation of welds. This allows such stressed areas to be reinforced without significant additional effort.

[0019] Furthermore, the weld seams can also follow geometric patterns, i.e., parallel lines and / or intersecting lines, and can be specifically and precisely formed. Additionally, the lines can also be wavy or zigzag-shaped, for example, to avoid creating an undesired preferred direction.

[0020] In particular, the formation of laser welds is suitable for hardening an area, since outside the laser weld, i.e. in intermediate line areas, there is no relevant thermal stress on the steel material, e.g., no martensite formation, so that larger areas can be formed by several welds without affecting the sheet material.

[0021] The welds are therefore reinforcing welds, i.e., they do not serve to connect to another component.

[0022] Such vehicle seat components can be, for example, a seat side panel that, in the event of a crash, is deformed in a buckling or bulging area, but also incorporates crossbars or tubes for lateral stability, which are subjected to separate loads and, for example, should not release the crossbar or tube even in a crash. Furthermore, swing arms or couplings are also articulated to such a seat side panel. The swing arms or couplings themselves, or, for example, other structural parts of the vehicle seat for seat cushion adjustment, can also be specifically designed with deformation zones and hardened areas. Rails, i.e., a lower or upper rail, as well as parts of the backrest, such as side rails, can also be specifically designed as vehicle seat components according to the invention.

[0023] In this manufacturing process, the vehicle seat component is formed from a steel plate or sheet, e.g., by punching or otherwise creating holes for subsequent attachments, and possibly by flanging and other deformations that increase stiffness. Subsequently, a hardened area, and in particular a deformation zone between two hardened areas, can be formed by one or more welds, preferably using a laser welding process.

[0024] The invention is explained in more detail below with reference to the accompanying drawings, which illustrate several embodiments. The drawings show: Fig. 1 a vehicle seat component in side view with hardened areas and deformation areas; Fig. 2 a vehicle seat with several vehicle seat components; Fig. 3 different line patterns for creating hardened areas.

[0025] A in Fig. The vehicle seat 1, shown in Figure 2 with its structural components, has several structural components, including two seat side panels 3 (side profiles) in its seat section 2, control arms 4 and 5 (swing arms) for adjusting the height of the seat section 2, and, for example, two backrest supports 7 in its backrest 6. These vehicle seat components 3, 4, 5, 7 are designed as essentially planar components made of sheet steel or steel plates. The vehicle seat 1 is essentially symmetrical with respect to its right and left sides, so that the essentially corresponding vehicle seat components 3, 4, 5, 7 are connected by, for example, cross tubes 8, 9, 10 or crossbars, which can be rigidly mounted or rotatably mounted in crossbar receptacles 12 of the vehicle seat components 3, 4, 5, 7, depending on the load and the kinematics to be developed.

[0026] Other relevant vehicle seat components are according to Fig. 2 a lower rail 14, an upper rail 15 for longitudinal adjustment of the vehicle seat 1, and in principle also the connecting parts or cross tubes 8, 9, 10 themselves.

[0027] The vehicle seat 1 is designed to be crash-resistant, particularly in the event of a rear-end collision or a frontal collision, to absorb the resulting deformations. Therefore, some or all of the vehicle seat components 3, 4, 5, 7 are designed to be deformable in order to dissipate the forces by absorbing energy and thus minimizing the stress or risk to the occupant.

[0028] Fig. Figure 1 shows a vehicle seat component 3, which can be, for example, a seat side panel 3 or a side profile of a seat part 2, shown in more detail in some embodiments. The vehicle seat component 3 is thus made of a sheet of steel, which may optionally be three-dimensionally profiled or formed, e.g., also with a folded or crimped edge. The vehicle seat component 3 has hardened areas 20, 21, two of which are shown here, e.g., in the area of ​​the receptacles 12 for the cross tubes 8, 9. However, other areas can also be hardened; for example, in addition to the receptacles 12 for the front cross tube 8 and rear cross tube 9, the connection of the control arms 4, 5 are also subject to greater loads and are therefore preferably hardened. According to Fig. 2 are, for example, hardened areas 20, 21 formed around the receptacle 12, or the receptacles 12 are formed in the hardened areas 20, 21.

[0029] Between the hardened areas 20, 21, a deformation zone 22, e.g., a buckling zone or a kinking zone, is formed. In the event of an overload or a crash, a controlled deformation should therefore occur in the deformation zone 22.

[0030] The hardened areas 20, 21 are provided with several welds 25, 26, which are e.g. according to Fig. 1 essentially have a longitudinal extension, or run largely in the same direction or even parallel between their endpoints 25a, 26a, forming a knot-like structure 27, in which inner welds 26, which adjoin the receptacles 12 or recesses of the receptacles 12, are closer together at a greater distance from the receptacles 12, and subsequently, in their further course, surround or run around the receptacle 12 in the vicinity of it. The welds 25, 26 thus form the knot-like structure 27 around the receptacles 12, wherein, advantageously, the welds 26, 25 adopt the shape or structure of the receptacles 12 to a lesser extent at a greater distance, i.e., at a greater distance from the receptacle 12, they run, for example, more straight and with less indentation. Close to the inlet 12, closed or ring-shaped welds 28 can also run around the inlet 12 accordingly. Fig. 3 h) will be trained.

[0031] Thus, the hardened areas 20, 21 can be formed solely by forming the welds 25, 26 on or in the sheet metal material 16 of the vehicle seat component 3. The welds 25, 26 are formed by laser welding, i.e., the sheet metal material 3 is briefly heated intensely by a laser during the welding process, advantageously resulting in martensite formation.

[0032] The hardening of the hardened area 20, 21 can thus be adjusted by the number and density of the welds 25, 26, 28, as well as their spacing, and possibly also the thickness or intensity of the weld formation of the welds 25, 26, 28. The dimensions of the hardened area 20, 21 are determined by the dimensions of the welds 25, 26, 28; in particular, the endpoints 25a, 26a and the outer welds 25 determine the dimensions of the hardened area 20, 21.

[0033] The lines or alignment of the welds 25, 26 can be adapted to the forces to be introduced or the relevant forces, e.g., by transverse tubes in the mounts 12, as well as forces in the event of a crash during deformation. According to Fig. 1. Hardened areas 20, 21 are thus provided around the mounts 12, so that transverse tubes 8, 9 connected here remain mounted even in the event of deformation, but the deformation area 22, e.g., buckling area or bulging area, undergoes a targeted deformation.

[0034] Preferably, a deformation area 22 is provided between two hardened areas 20, 21, so that it can deform in a defined manner, e.g., buckle.

[0035] Thus, not the entire hardened area 20, 21 is subjected to a temperature treatment; the sheet material in intermediate line locations 29 between the welds 25, 26, 28 remains essentially intact, since the heat input during laser processing allows for a very targeted, point-specific force application only in the lines.

[0036] In Fig. Figure 3 shows some line patterns 30a, b, c, d, e, f, g, h, i, each formed from several welds 25 and / or 26 and / or 28. According to Fig. 30a and b are welds 25 running concurrently or even parallel, e.g. also with the same distance, each in an essentially square or right-angled form, with the welds 25 running parallel to a side edge of the rectangle, or non-parallel (checkerboard, trapezoidal), according to 30c wavy, i.e. with several, similarly or even parallel, spiral welds 25, according to line pattern 30d through intersecting welds 25, e.g. parallel welds 25 intersecting at right angles, possibly also with a variation of the distances.

[0037] The line pattern 30e shows several interrupted welds 25, or a dashed design of the welds 25; by placing the individual welds 25 sufficiently close together, the individual welds 25 thus form a common line pattern.

[0038] According to the line pattern 30f, in modification to 30 a), the distance between the individual welds 25 d is varied, in particular increased outwards, so that the hardness decreases laterally towards the edge, The line pattern 30g shows a zigzag pattern, so that the weld seams 25 can lie close together without forming a preferred direction as with a parallel pattern.

[0039] The line pattern 30h shows a concentric or substantially concentric course, which is particularly helpful for stabilizing a central image 12; the lines 28 may also be, for example, elongated or bulging.

[0040] Fig. 3i then shows the one already in Fig. 2 shown knot-like structure 27 for strengthening a receptacle 12 or another area, wherein optionally an annular weld 28 can first run (concentrically or non-concentrically) around the receptacle 12, and the subsequent welds 25 and 26 extending outwards can gradually transition into a uniform or straight line pattern.

[0041] Thus, the arrangement of the welds 25, 26, 28 can follow geometric patterns, i.e. lines, circles, etc., or ionic principles such as tree ring structures around knot holes.

[0042] The desired component behavior of the vehicle seat component 3, 4, 5, 7 can be achieved in the case of deformation by buckling, bulging, folding.

[0043] In the manufacturing process, in step St1, the basic part of the respective vehicle seat component 3, 4, 5, 7 can first be cut out from a steel plate or sheet, or, for example, from a tube as a semi-finished product, optionally with punching of holes, recesses 12, and forms to create a profile or edge. In step St2 – after or even before the forming or cutting – the weld seams 25, 26, 28 are formed using a laser, which can also be used, for example, to connect components such as the cross tubes 8, 9, 10 in the recesses.

[0044] Therefore, steps St1 and St2 can also be performed in reverse order.

Claims

[1] Vehicle seat (1) comprising two vehicle seat components (3, 4, 5, 7) and a crossbar or cross tube (8, 9, 10), wherein each vehicle seat component (3, 4, 5, 7) has at least one deformation area (22) for at least partial plastic deformation, wherein each vehicle seat component (3, 4, 5, 7) has at least one receptacle (12) for components (8, 9, 10) to be attached as a reinforced, loaded area (20, 21) which is designed as a hardened area and adjoins or connects to the deformation area (22), wherein the hardened areas (20, 21) each have several welds (25, 26, 28), wherein the crossbar or cross tube (8, 9, 10) is received between the two vehicle seat components (3, 4, 5, 7) and is positioned and secured by the receptacle (12) of each of the two vehicle seat components (3, 4, 5, 7), wherein the welds are laser welds (25, 26, 28) and the steel material is hardened by local heating with complete or partial martensite formation, wherein intermediate line areas (29) of the hardened area (20, 21) between the welds (25, 26, 28) are formed without heat treatment and / or without martensite formation, where at least some of the several welds (25, 26, 28) are linear in form, wherein in each of the vehicle seat components several welds (26) encircle the receptacle (12) as a loaded area (12) or at least partially or locally surround it, and at least some welds (25, 26, 28) encircle the loaded area (12) to be reinforced with a greater curvature and run more straight or with less curvature outside the loaded area (12) to be reinforced to form a knot-like structure (27), wherein the deformation area (22) is arranged between two hardened areas (20, 21) and the deformation area (22) is designed as a buckling area or bulging area for buckling between the two hardened areas (20, 21) in the event of a deformation load, e.g. an accident, so that the vehicle seat components (3, 4, 5, 7) are selectively deformable in at least one deformation area (22) when subjected to high loads and in a crash, [2] Vehicle seat (1) according to claim 1, characterized by , that the linear welds (25, 26, 28) are formed as straight or curved lines. [3] Vehicle seat (1) according to any one of the preceding claims, characterized by , that the several welds (25, 26, 28) are arranged next to each other, in particular with a substantially uniform or parallel course to each other. [4] Vehicle seat (1) according to any one of the preceding claims, characterized by , that the multiple welds (25, 26, 28) form a line pattern or structure, e.g. with a wavy, zigzag, straight or intersecting pattern of the multiple welds (25, 26, 28). [5] Vehicle seat (1) according to any one of the preceding claims, characterized by , that the endpoints (25a, 26a) of the multiple welds and the course of the outer welds (25, 26) define the hardened area (20, 21), e.g. with a rectangular shape. [6] Vehicle seat (1) according to any one of the preceding claims, characterized by that at least one weld seam is closed in itself or has a ring-shaped profile. [7] Vehicle seat (1) according to any one of the preceding claims, characterized by , that the welds (25, 26, 28) run with decreasing curvature around the loaded area (12) as they move further away from it. [8] Vehicle seat (1) according to any of the preceding claims, characterized by , that at least one weld (25, 26, 28) is formed without a joining function. [9] Vehicle seat (1) according to any of the preceding claims, characterized by that it is made of a sheet or plate of steel and that at least one weld (25, 26, 28) is formed on a top surface (16a, 16b) or extends from one top surface (16a) to the other top surface (16b) through the sheet or plate of steel. [10] Vehicle seat (1) according to any of the preceding claims, characterized by that it is trained from the following group: Seat side panel (3), swing arm (4, 5), backrest support or backrest side panel (7), lower rail (14), upper rail (15). [11] Method for manufacturing a vehicle seat (1) according to any one of claims 1 to 10, comprising at least the following steps: Manufacturing two vehicle seat components (3, 4, 5, 7), using the following steps: Cutting or punching out a basic part from sheet steel or a steel plate (St1), thermal forming of several welds to form a hardened area (20, 21) and at least one non-hardened deformation area (22) adjacent to the hardened area (20, 21) (St2), Insert a cross tube or crossbar between the vehicle seat components (3, 4, 5, 7) and secure it in the receptacles (12) of the two vehicle seat components (3, 4, 5, 7). [12] Method according to claim 11, characterized by that the multiple weld seams are formed by a laser welding process under the guidance of a laser line at a defined distance from each other.

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