Vehicle floor panel arrangement

Abstract

The invention relates to a vehicle floor panel arrangement (5) with a vehicle floor panel (4) as a component of a motor vehicle body (1) having a flat floor and a forming (8) on two opposite longitudinal sides and two opposite end faces, with respect to the vehicle vertical direction (Z) downwards, such that a hood-like body is formed by the vehicle floor panel (4), characterized in that the vehicle floor panel (4) is manufactured in one piece from a sheet metal blank in a press stroke and that the vehicle floor panel (4) closes a battery box upwards in the vehicle vertical direction (Z), wherein the vehicle floor panel (4) optionally has areas with different tensile strength and / or different wall thickness.

Description

The present invention relates to a motor vehicle body comprising a vehicle floor panel arrangement according to the features in the preamble of claim 1.Motor vehicle bodies are known from the prior art. These are used in motor vehicles, in particular passenger motor vehicles. Passenger vehicles are driven by an internal combustion engine drive, but increasingly also by an electric drive.DE 10 2011 017 459 A1 discloses a motor vehicle having a battery box for receiving at least one traction battery, wherein the battery box is arranged in the region of a supporting floor structure of the vehicle body.US 7 997 368 B2 provides a battery case that enables a sealing member provided at a connection part between a tub member and a cover member to prevent the torque control of the threaded part from interfering with.Furthermore, DE 10 2004 037 789 B3 shows a floor assembly for a motor vehicle which is improved with regard to production and safety and deformation behavior.Such a self-supporting body is produced from individual sheet metal components produced by forming. These sheet metal components are usually produced from steel sheet alloys, and in further individual cases also from aluminum components. For this purpose, individual components, such as an A-pillar, a B-pillar, a C-pillar, various longitudinal beams or cross beams, are produced individually and subsequently assembled by joining to form the self-supporting body.Hot forming and press hardening technology is also used for individual components. Hereby, tensile strengths of more than 1,000 MPa can be set on a hardenable steel alloy.It is the object of the present invention to provide a vehicle floor panel which can be produced easily in terms of production costs, but also cost-effectively, is improved in terms of its geometric precision, and has different connection possibilities for further components and the specific setting of crash properties.The aforementioned object is achieved in a motor vehicle body having the features in claim 1.Advantageous embodiment variants are the subject of the dependent claims.The vehicle floor panel arrangement has a vehicle floor panel as a component of a motor vehicle body. For this purpose, a vehicle floor panel is produced in one piece by forming and then inserted into a self-supporting motor vehicle body. For this purpose, the vehicle floor panel has a flat floor and a forming on two opposite longitudinal sides and two opposite end sides. The forming refers to the motor vehicle vertical direction downwards. Instead of a forming, reference can also be made to a formed edge or a circumferential edge.This produces a hood-like body or a hood-like trough. This hood-like body forms the vehicle floor panel. The opening of the hood-like body is directed downward with respect to the vehicle vertical direction in the installed state in the vehicle body. Thus, according to the invention, with regard to the possible functional integration, it is achieved that the vehicle floor panel, which forms the floor or downward the termination of the passenger compartment, simultaneously also forms an upper hood of an electrical energy store or of a drive battery. The vehicle floor panel thus also forms the upper part or the upper hood of the battery box. In particular, the downward shaped part or the edge is provided with a flange, so that the lower part of a battery box can be coupled therewith.At the same time, according to the invention, the vehicle floor panel is furthermore produced in one piece from a panel blank in a press stroke on a large press. The vehicle floor panel has regions with different tensile strength and / or different wall thickness. By means of this measure, in locally required regions, a higher strength, for example, can be provided by means of a higher wall thickness or else a higher strength when using the hot forming and press hardening technique of tailored tempering and therefore an increased tensile strength. The regions with higher strength have in particular a tensile strength of greater than 1,000 MPa, in particular greater than 1,350 MPa, particularly preferably greater than 1,500 MPa and very particularly preferably greater than 1,800 MPa, in individual cases even greater than 2,000 MPa.Particularly preferably, for example, areas can be reinforced which must have particular connection strengths. This can be, for example, a molded-in cross member running transversely to the direction of travel, which simultaneously also serves as a seat cross member. At the same time, this also serves for stiffening the motor vehicle body produced and for stiffening the passenger compartment, especially during a side crash. Such a cross strut then has a high tensile strength and / or increased wall thickness locally over its longitudinal course, wherein the longitudinal course is oriented in the transverse direction of the motor vehicle.In the context of the invention, "one-piece" means that a sheet metal blank is used. The sheet metal blank itself can be formed in one piece and in the same material. However, the sheet metal blank can also be provided as a tailored rolled blank or tailored welded blank. In the latter case, and therefore in the case of a tailored welded blank, locally different wall thicknesses and / or locally different material properties can be used in order to form the later desired strengths in specifically local regions. In the case of a tailored welded blank, the individual sheet metal layers are preferably placed butt against one another and welded, in particular laser-welded. However, overlap regions can also be present, which are then spot welded, for example. According to the invention, a further advantage is distinguished in that this sheet metal blank is then provided completely before the actual forming. The entire floor panel is then produced using hot forming and press hardening technology in a forming process or a forming press and in a press stroke. If the floor panel is produced as a cold-forming component, this can also be formed in a plurality of stages, but can always be formed as a whole component in a forming press. As a result, compared to methods known from the prior art, the geometric precision can be significantly increased in the case of individual arrangements.At the same time, further additional components can be dispensed with, since otherwise longitudinal and cross members are used in the floor region of a motor vehicle body and corresponding floor panels are then used only as closing panels or therebetween. The stiffening functions, for example of longitudinal and cross members, can be integrated into the floor panel by means of corresponding depressions and / or locally fixed regions. At the same time, the functional integration of a hood of a battery box is also formed. The overall production cost of the motor vehicle body is thus likewise reduced due to the fact that different individual components do not have to be produced individually and subsequently joined together.The overall dimension of the floor panel is thus more than 80 cm x 100 cm, preferably more than 100 cm x 150 cm. The vehicle floor panel extends substantially in the motor vehicle body in the motor vehicle transverse direction from one sill to the opposite sill. With respect to the motor vehicle longitudinal direction, the vehicle floor panel extends substantially from an end wall or fire protection wall in the front region of the motor vehicle as far as a rear bench support in the rear region of the motor vehicle.Preferably, at least individual metal sheets, in particular in the case of a tailored welded blank, are selected from the alloy specifications mentioned below. Ductile ranges between 500 MPa and 1,000 MPa, or 500 MPa to 850 MPa or even less than 450 MPa can then be set accordingly. In the case of high-strength or higher-strength or highest-strength regions, corresponding data of more than 1,000 MPa are established by using hot forming and press hardening technology.The types of steel used can be used below by way of example. In particular, different types of steel can be combined with one another in a tailored welded blank. Corresponding strength ranges for hard or soft regions or solid or ductile regions can be gathered from the table. All the alloy constituents are stated in wt %, with residual iron and melting-related impurities then being added to the respective hardenable steel alloyFurther advantages, features, properties and aspects of the present invention are the subject matter of the following description. Preferred design variants are shown in schematic figures. They serve to facilitate understanding of the invention. The following are shown: FIG. 1 shows a motor vehicle body for a motor vehicle as a partial detail, FIGS. 2 a, band c show a plan view, a longitudinal section and a cross-sectional view of a vehicle floor panel arrangement according to the invention, FIGS. 3a, b and c show a further embodiment of the invention, FIGS. 4a, b and c show an alternative embodiment of FIG. 2, FIGS. 5a, b and c show a further alternative embodiment variant to FIG. 4; and FIGS. 6 a, band c show a further alternative embodiment variant.FIG. 1 shows a motor vehicle body 1 for a motor vehicle as a partial section. An A-pillar 3 indicated at the front and a sill 2 can be seen. A floor panel 4 is placed underneath the motor vehicle body 1, so that a vehicle floor panel arrangement 5 is realized as a result. Furthermore, longitudinal beams 6 located opposite the front are formed and a rear bench support 7 is formed in the rear region.FIGS. 2 a, band c show a plan view, a longitudinal section and a cross-sectional view of a vehicle floor panel arrangement 5 according to the invention.The vehicle floor panel 4 according to the invention has a frame or a forming 8 all around, which is formed downward with respect to the motor vehicle vertical direction Z. It can thus be designed as a circumferential frame 8. Opposite this, a circumferential flange 9 is arranged to be coupled to a lower shell or trough 10, so that a battery carrier 11 is formed overall. The vehicle floor panel 4 thus forms the upper hood of the battery carrier 11 as it were. It extends over the entire vehicle floor, thus with respect to the transverse direction Y of the motor vehicle, from one sill 2 to the opposite sill 2, with respect to the longitudinal direction X of the motor vehicle, from a front splash guard or fire guard wall as far as the rear rear rear bench panel. Furthermore, a cross member 13 is formed in which at the same time comprises receptacles 14 and is thus designed as a seat cross member. Sleeves 15 can extend below the receptacles 14. These sleeves 15 serve as reinforcements or spacers. In the rear region in the vertical direction, a hood-like depression 16 is then formed. This hood-like depression 16 can serve, for example, for receiving power electronics, not shown in detail, of the batteries which are arranged in the battery carrier 11, which is not shown in detail here, however. In particular, for example in the region of the cross member or the transverse bead 13, a high-strength region can be formed. Adequate rigidity in the motor vehicle transverse direction Y is thus achieved.FIGS. 3 a, band c show a further embodiment, especially taking into account either greater or lesser wall thickness and / or increased or lesser tensile strength and / or the arrangement of a corresponding patch 17. The entire vehicle floor panel 4 is formed as a single-piece component. For this purpose, a sheet metal blank is first provided as a tailored welded blank. In a region which is at the front in the motor vehicle longitudinal direction X, a greater wall thickness 18 is thus formed. Alternatively, a greater tensile strength can also be formed here. Subsequently, a wall thickness 19 that is smaller in relation thereto is then formed or a lower tensile strength. In a rear region, a greater wall thickness is then again formed; alternatively or additionally, a greater tensile strength can be formed.According to FIG. 3 b, a thicker or larger wall thickness 18 is preferably arranged in the front and rear regions in the motor vehicle longitudinal direction. This serves for stiffening for a frontal crash or a rear crash. In the case of a seat cross member arranged with a greater wall thickness 18, the rigidity in the event of a side crash is thereby increased.FIGS. 4 a, band c show an alternative embodiment variant to FIG. 2 In this case, the transverse bead 13 is likewise provided with a patch 17 which extends over the entire motor vehicle width with respect to the motor vehicle transverse direction Y.FIGS. 5 a, band c show a further alternative embodiment variant to FIG. 4 In this case, a patch 17 is again placed in the rear region of the depression 16. This patch 17 also extends over the entire width of the motor vehicle, as shown in FIG. 5c.FIGS. 6 a, band c show a further alternative embodiment variant. In this case, the circumferential deformation 8 on the vehicle floor panel 4 is formed only slightly in the motor vehicle vertical direction Z. This also has a circumferential flange. In the rear region, a second transverse bead is formed, which extends substantially over the entire width of the floor panel in the transverse direction of the motor vehicle.The types of steel used can be used below by way of example and can be used for all variants of this invention. In particular, different types of steel can be combined with one another in a tailored welded blank. Corresponding strength ranges for hard or soft regions or solid or ductile regions can be gathered from the table. All the alloy constituents are stated in wt %, with the respective hardenable steel alloy then being admixed with the remainder iron and melting-related impurities Reference Number:1 Motor vehicle body 2 sill 3 A-pillar 4 vehicle floor panel 5 vehicle floor panel arrangement 6 longitudinal member 7 rear bench support 8 forming / frame 9 flange 10 shell / trough 11 battery carrier 12 not allocated 13 cross member / transverse bead 14 receptacle 15 sleeve 16 trough 17 patch 18 greater wall thickness 19 lesser wall thickness X motor vehicle longitudinal direction Y motor vehicle transverse direction Z motor vehicle vertical direction

Claims

Motor vehicle body (1) having a vehicle floor panel arrangement (5) with a vehicle floor panel (4) with a flat floor and, on two opposite longitudinal sides and two opposite end sides, a forming (8) downwards, in relation to the motor vehicle vertical direction (Z), in such a way that a hood-like body is formed by the vehicle floor panel (4), characterized in that the vehicle floor panel (4) is produced in one piece from a sheet blank in a press stroke as a hot-forming and press-hardening component, and in that the vehicle floor panel (4) tightly seals a battery box upwards in relation to the motor vehicle vertical direction (Z), wherein the vehicle floor panel (4) has regions with different tensile strength and / or different wall thickness.Motor vehicle body (1) comprising a vehicle floor panel arrangement (5) according to claim 1, characterized in that a high-strength region has a tensile strength greater than or equal to 1350 MPa.Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that soft regions are formed which have a tensile strength Rm of less than 1000 MPa.Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that the vehicle floor panel (4) extends in the motor vehicle transverse direction (Y) substantially from a sill (2) to an opposite sill (2).Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that the vehicle floor panel (4) has a circumferential flange (9) for coupling to a lower shell (10) of a battery box.Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that a hood-like depression (16) is worked in by forming in a rear section of the vehicle floor panel (4) with respect to the motor vehicle longitudinal direction (X), wherein power electronics and / or cooling fluid pump of a drive battery is used in the hood-like depression (16).Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that at least one transverse bead (13) is formed in the vehicle floor panel (4), in such a way that the transverse bead (13) is formed as a seat cross member.Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that foot space depressions are formed downwards with respect to the motor vehicle vertical direction (Z).Motor vehicle body (1) having a vehicle floor panel arrangement (5) according to one of the preceding claims, characterized in that a patch (17) is applied at least locally, in such a way that a double layer is formed.

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