Vehicle door with a door impact beam

Abstract

Vehicle door for a body side structure of a two-track vehicle, comprising a door frame (7) in which a door impact beam (9) bridging the door frame (7) in the longitudinal direction (x) of the vehicle is arranged, the door impact beam being a base sheet part (11) with a profile space (21) open outwards in the transverse direction (y) of the vehicle, wherein the base sheet part (11) has at least one hat-shaped or U-shaped profile in cross-section, with at least one crash-away inner profile base (17) and side flanks (19) raised therefrom, which together define the profile space (21), and wherein the U-profile of the base sheet part (11) is part of a corrugated profile (15) in which the side flanks (19) connect the at least one crash-away inner profile base (17) with at least one crash-facing outer profile base (25), and wherein the inner profile base (17) has a profile in a Side impact (F A) highly stressed location with a tension zone prone to cracking (F Z) which is locally reinforced by a reinforcing sheet metal part (13), wherein the reinforcing sheet metal part (13) is designed as a patch that is continuously in full-surface contact with the base sheet metal part (11) in a welded connection, namely in a tailored-blank connection, wherein the reinforcing sheet metal part (13) is contour-adapted in full-surface contact with the U-profile of the base sheet metal part (11), namely on the crash-facing side of the base sheet metal part (11), wherein the reinforcing sheet metal part (13) has a crash-away profile bottom (31) with adjoining side flanks (33) which are in full-surface contact with the crash-away profile bottom (17) and the side flanks (19) of the base sheet metal part (11), and wherein the reinforcing sheet metal part side flanks (33) are extended with an edge web (35) which is in contact with the crash-facing, vehicle-outer profile bottom (25) of the base sheet part (11).

Description

[0001] The invention relates to a vehicle door according to claim 1.

[0002] To protect vehicle occupants, door impact beams may be installed in the doors of a vehicle, which allow the impact energy to be directed into the body structure via the door in the event of a side crash.

[0003] German patent application DE 43 00 898 C1 discloses an exemplary vehicle door for a body side structure of a vehicle, in which such a door impact beam can be installed in a door frame of the vehicle door. For increased stiffness, the door impact beam has an approximately U-shaped profile structure with a profile cavity open outwards in the transverse direction of the vehicle. At a point subjected to high stress in a side crash, the base sheet metal part is locally reinforced by a reinforcing sheet metal part. In DE 43 00 898 C1, the reinforcing sheet metal part is designed as a cover plate that covers the profile cavity, forming closed profile chambers, and is welded to the base sheet metal part.

[0004] In DE 43 00 898 C1, the component assembly consisting of the base sheet metal part and the reinforcement sheet metal part has a high component weight. Furthermore, the microstructure of the sheet metal parts is altered at the welded joints between the base sheet metal part and the reinforcement sheet metal part, thereby impairing the crash behavior of the door impact beam.

[0005] When using press-hardened steels, the wall thickness of the base sheet metal component, and therefore its weight, can be reduced. However, this reduced wall thickness can lead to local instabilities in a side-impact crash. In the tensile-loaded area of ​​the door impact beam, this initially results in high plastic deformations and subsequently, due to the low ductility of press-hardened steels, to an increased risk of cracking.

[0006] From DE 100 49 660 B4, a method for manufacturing a structural component consisting of a base plate and a smaller, locally arranged reinforcing plate is known. The base plate and the reinforcing plate are brought into a patch connection in a partially formed preformed state. Subsequently, hot forming takes place, in which the component assembly is first heat-treated and then hot-formed in a deep-drawing press.

[0007] The object of the invention is to provide a vehicle door for a body side structure of a vehicle and a method for manufacturing a door impact beam in which the risk of cracking in the door impact beam in the event of a side crash is reduced despite a reduced component weight.

[0008] The problem is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

[0009] The invention is based on the fact that, in a press-hardened door impact beam, a reduced wall thickness leads to an increased risk of cracking, causing the load path provided by the door impact beam in a side-impact crash to fail prematurely during the crash. Against this background, according to claim 1, the reinforcing sheet metal part is no longer welded to the base sheet metal part as a cover sheet known from the prior art, but rather, to reduce weight, is continuously and fully connected to the base sheet metal part as a so-called patch, specifically in a tailored-blank connection.

[0010] In this way, at the highly stressed point of the door impact beam in a side-impact crash, a reduction in plastic strain in the tensile area of ​​the door impact beam facing away from the impact point can be achieved through the following two distinct effects: Firstly, the reinforcing sheet metal patch provides a doubling of material in the tensile (crash-facing) area of ​​the door impact beam, thereby reducing tensile stresses and thus also plastic strains. Secondly, an additional doubling of material in the compression (crash-facing) area increases the stability of the door impact beam's cross-section. This means that the consequences of local instability (i.e., locally high plastic strains in the tension-loaded area of ​​the door impact beam in a side-impact crash) are no longer concentrated in a small area, but are spread over a larger surface.

[0011] Overall, compared to the prior art, the patch connection according to the invention significantly reduces plastic deformation and thus the risk of cracking in the door impact beam. Furthermore, the use of such a patch connection allows for a weight-optimized solution to be achieved even with a four-cavity tool.

[0012] Further aspects of the invention are described below, which relate in particular to the cross-sectional geometry of the door impact beam in the area of ​​the reinforcement plate section: The base plate section can have at least a hat-shaped or U-shaped profile in cross-section. The U-profile can be composed of a crash-away, vehicle-inside profile base and side flanks extending upwards from it, which together define the profile space. The U-profile results in increased stiffness in the door impact beam.

[0013] The reinforcing plate is contour-adapted and fully bonded to the U-profile of the base plate. To ensure particularly favorable crash performance of the door impact beam, the reinforcing plate is positioned on the crash-facing side of the base plate.

[0014] To further increase component stiffness, the U-profile of the base sheet is part of a corrugated profile, in which the side flanks of the U-profile transition into a crash-facing, vehicle-outer profile base as the cross-section extends. Side flanks can connect to the crash-facing profile base, each terminating in a crash-facing, vehicle-inner profile base.

[0015] As mentioned above, the reinforcing plate is only welded locally to the base plate at one location that is subject to high stress in the event of a side impact. Accordingly, to reduce weight, the reinforcing plate is positioned with a greater distance to the longitudinal edges and end faces of the base plate.

[0016] With a view to contour-adapting design, the reinforcement sheet metal part has a crash-facing, interior profile base with raised side flanks. Both the profile base and the side flanks of the reinforcement sheet metal part are in full contact with the profile base and the side flanks of the base sheet metal part.

[0017] The door impact beam wave profile described above has at least one crash-facing, outer profile base, which runs approximately in a plane defined by the vehicle's longitudinal and vertical directions, and at least one crash-away, inner profile base, which also runs in a plane defined by the vehicle's longitudinal and vertical directions. In a side impact, the crash-facing, outer profile base forms a load path subjected to compressive stresses, in which the compressive stresses act in the longitudinal direction of the vehicle. In contrast, the crash-away, inner profile base forms a load path subjected to tensile stresses, in which the tensile stresses act in the longitudinal direction of the vehicle.With the patch according to the invention (i.e. the reinforcing sheet part) a material doubling can be achieved at least in the crash-facing, vehicle interior profile floor, whereby the tensile stresses and thus also the plastic strains in the crash-facing profile floor can be reduced.

[0018] The reinforcing plate side flanks are each extended with an angled edge rib. This rib encompasses a transition edge between the base plate side flank and the crash-facing base plate profile base and is in contact with the crash-facing base plate profile base. In this way, the reinforcing plate is effective not only in the tensile area away from the crash but also in the compression area of ​​the door impact beam facing the crash, thereby increasing the cross-sectional stability of the door impact beam in a side impact.

[0019] For further weight reduction, it is preferred if the reinforcing sheet metal part is not extended directly to the end faces of the base sheet metal part, but rather is spaced a greater distance from the attachment points of the base sheet metal part to the door frame.

[0020] As already indicated above, the invention is particularly applicable to press-hardened door impact beams. To manufacture such a door impact beam, a sheet metal blank forming the base sheet and a sheet metal blank forming the reinforcement sheet are first prepared and welded together to form a composite component. This is followed by hot forming, in which the composite component is first heat-treated in an oven and then hot-formed and simultaneously quenched in a deep-drawing press. This results in a composite component with uniform material quality. Any impairment of material quality due to weld joints, as is the case in DE 43 00 898 C1 above, is thus prevented.

[0021] The advantageous embodiments and / or further developments of the invention described above and / or set out in the dependent claims can be used individually or in any combination with each other, except for example in cases of clear dependencies or incompatible alternatives.

[0022] The invention and its advantageous embodiments and / or further developments, as well as their advantages, are explained in more detail below with reference to drawings.

[0023] They show: Fig. 1. A two-track motor vehicle in a side view with partial elevation; Fig. 2 a door impact beam in standalone position; Fig. 3 a sectional view along the cutting plane AA from the Fig. 2; Fig. 4 a view illustrating a method for manufacturing the door impact beam; Fig. 5 in a perspective partial view the door impact beam in the event of a side crash; and Fig. 6 a view according to the Fig. 3 according to a second embodiment.

[0024] In the Fig. Figure 1 shows a two-track vehicle in a side view, the body's side structure of which includes a front A-pillar 1, a middle B-pillar 3, and a rear C-pillar 5. A driver's door 5, shown in partial elevation, is positioned between the A-pillar 1 and the B-pillar 3. As can be seen from the partial elevation, the driver's door 5 has a door frame 7, the frame members of which are spaced apart x from each other in the longitudinal direction of the vehicle and are connected to each other via a door impact beam 9 to transmit force.

[0025] In a side-impact collision of the vehicle against a side crash barrier, impact energy F A ( Fig. 5) introduced in a transverse vehicle direction y into the door impact beam 9, which absorbs the impact energy F A the load is transferred to the adjacent body structure. Upon reaching a critical breaking load level, the door impact beam 9 breaks / tears apart, causing the load path formed by the door impact beam 9 to fail and extend into the adjacent side body structure, which can lead to an adverse intrusion hazard for the vehicle interior.

[0026] In the Fig. Figure 3 shows the cross-sectional geometry of the door impact beam 9, by means of which the aforementioned critical breaking load level of the door impact beam 9 is increased. Accordingly, the door impact beam 9 is constructed in two parts with a base plate part 11 and a reinforcing plate part 13, which is located in the Fig. 2 is highlighted by hatching. The reinforcing sheet metal part 13 is located approximately in the middle area 14 ( Fig. 2) of the base plate part 11, which is subjected to high loads in the event of a side crash. To increase the transverse stiffness, the base plate part 11 has a corrugated profile 15, which is located in the Fig. 3 has a central, crash-away inner profile floor 17, from which side flanks 19 extend upwards towards the outside of the vehicle. The side flanks 19, together with the inner profile floor 17, define a profile space 21 open to the outside of the vehicle. In the further cross-sectional path, the two side flanks 19 each transition at rounded transition edges 23 into a crash-facing, outer profile floor 25. Further side flanks 19 adjoin the outer profile floor 25, which in turn extend to inner profile floors 17, which are bounded by longitudinal edges 29 of the base sheet component.

[0027] As from the Fig. As can be seen from Figure 3, the wave profile 15 is designed in a mirror image with respect to a central plane M oriented perpendicular to the profile base 17.

[0028] The vehicle interior profile floor 17 and the adjoining side flanks 19 are fully welded to the reinforcement sheet metal part 13 on their crash-facing side, forming a so-called tailored-blank connection. The reinforcement sheet metal part 13 is contour-adapted and also has a profile floor 31 and adjoining side flanks 33, which are fully in contact with the profile floor 17 and the side flanks 19 of the base sheet metal part 11.

[0029] In the Fig. Figure 5 indicates a side-impact crash scenario in which the door impact beam 9 is subjected to crash energy F in the transverse direction of the vehicle y. Ais subjected to pressure. Consequently, the crash-facing outer vehicle profile floors form 25 load paths F subjected to compressive forces. D , while the crash-facing, vehicle-inside profile floors 17 tensile load paths F Z form and are therefore prone to cracking. In the case of the Fig. In the constellation shown in 5, in the event of a side crash, the upper and lower longitudinal edges of the base plate part 29 automatically shift away from the tension zone F - under self-relief. Z towards pressure zone F D , as indicated by the arrows. Accordingly, only the central inner profile floor 17 of the vehicle remains in the crack-prone tension zone F. Z . This is additionally stiffened by means of the reinforcing sheet part 13 in order to withstand the stresses in the tensile area F Zto reduce the very high risk of cracking. In this way, the critical breaking load level increases in the vehicle interior profile floor 17 of the door impact beam 9, up to which the door impact beam 9 can withstand loads without tearing apart.

[0030] The door impact beam 9 can preferably be manufactured by hot forming. For this purpose, according to the Fig. 4. First, a sheet metal blank 37 forming the base sheet metal part 11 and a sheet metal blank 39 forming the reinforcing sheet metal part 13 are provided. The sheet metal blanks 37 and 39 are welded together to form a component assembly and subjected to hot forming. In the hot forming process, the component assembly is heat-treated, for example, in a multi-chamber furnace, and then hot-formed and simultaneously quenched in a deep-drawing press.

[0031] The in Fig. 3 and Fig. The door impact beam shown in point 5 does not fall under claim 1. However, it illustrates the basis on which a Fig. The door impact beam shown in section 6 is based on section 9.

[0032] In the Fig. Figure 6 shows the door impact beam 9 according to a second embodiment. The structure and function of the reinforcing sheet metal part 13 installed therein are identical to the reinforcing sheet metal part 13 indicated in the preceding figures. In contrast to the Fig. 3 to 5, the side flanks 33 of the reinforcement sheet part 13 are extended upwards and downwards with edge webs 35, which encompass the transition edges 23 of the base sheet part 11 and are in contact with the two outer profiled base plates 25 of the base sheet part 11. In this way, partial material doubling is also achieved in the pressure area, thereby increasing the cross-sectional stability of the door impact beam 9 in the event of a side crash.

Claims

[1] Vehicle door for a body side structure of a two-track vehicle, comprising a door frame (7) in which a door impact beam (9) bridging the door frame (7) in the longitudinal direction (x) of the vehicle is arranged, the door impact beam being a base sheet part (11) with a profile space (21) open outwards in the transverse direction (y) of the vehicle, wherein the base sheet part (11) has at least one hat-shaped or U-shaped profile in cross-section, with at least one crash-away inner profile base (17) and side flanks (19) raised therefrom, which together define the profile space (21), and wherein the U-profile of the base sheet part (11) is part of a corrugated profile (15) in which the side flanks (19) connect the at least one crash-away inner profile base (17) with at least one crash-facing outer profile base (25), and wherein the inner profile base (17) in a side-impact crash (F A) highly stressed location with a tension zone prone to cracking (F Z) which is locally reinforced by a reinforcing sheet metal part (13), wherein the reinforcing sheet metal part (13) is designed as a patch that is continuously in full-surface contact with the base sheet metal part (11) in a welded connection, namely in a tailored-blank connection, wherein the reinforcing sheet metal part (13) is contour-adapted in full-surface contact with the U-profile of the base sheet metal part (11), namely on the crash-facing side of the base sheet metal part (11), wherein the reinforcing sheet metal part (13) has a crash-away profile bottom (31) with adjoining side flanks (33) which are in full-surface contact with the crash-away profile bottom (17) and the side flanks (19) of the base sheet metal part (11), and wherein the reinforcing sheet metal part side flanks (33) are extended with an edge web (35) which is in contact with the crash-facing, vehicle-outer profile bottom (25) of the base sheet part (11). [2] Vehicle door according to claim 1, characterized by, that the reinforcement plate part (13) terminates at a distance (Δz) from the longitudinal edges (29) of the base plate part. [3] Vehicle door according to claim 1 or 2, characterized by , that the edge web (35) encompasses a transition edge (23) between the side flank (19) and the crash-facing outer profile floor (25) of the base sheet part (11). [4] Vehicle door according to one of the preceding claims, characterized by , that the reinforcement plate part (13) is spaced apart from the attachment points of the base plate part (11) on the door frame (7) by a longitudinal offset (Δx).

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