The basic structure of a motor vehicle with a bumper

Abstract

Body shell structure (1) of a motor vehicle with a cross member (4) designed as a bumper, which is connected to the body shell (6) via deformation elements (3), wherein the deformation elements (3) are designed as closed hollow profiles (15) extending in the longitudinal direction of the motor vehicle and are arranged symmetrically to a center line (7) extending in the longitudinal direction of the motor vehicle, wherein each deformation element (3) has side walls (16) in which at least one groove (18) is formed, which runs perpendicular to the center line (7), wherein the cross member (4) is designed as a profile with two horizontally extending profile walls (10) and has a first boundary (12) facing the deformation elements (3) when viewed in the longitudinal direction of the motor vehicle and a corresponding second boundary (13) facing away from the deformation elements (3),wherein each deformation element (3) consists of two half-shells (14) and each deformation element (3) extends longitudinally beyond the first boundary (12) in the direction of the second boundary (13), wherein each deformation element (3) is spaced at least 5 mm from the second boundary (13), wherein the side walls (16) of each deformation element (3) are connected to each other via curved sections (17) such that the curved sections (17) form an angle of 90 degrees and connect the respective perpendicular side walls (16) to each other, wherein a groove (18) of a side wall (16) extends into the two curved sections (17) but not into adjacent side walls (16), wherein the deformation elements (3) are connected to the cross member (4) via connecting welds (22), characterized in thatthat the connecting welds (22) extend along the side walls (16) of each deformation element (3) and not into the curved sections (17).

Description

[0001] The present invention relates to a body shell structure of a motor vehicle with a cross member designed as a bumper, which is connected to the body shell via deformation elements according to the preamble of claim 1.

[0002] The closest prior art is the generic publication US 2009 / 0 001 737 A1, which describes a conically shaped deformation pot consisting of two half-shells, which is connected to the bumper cross member via tongues.

[0003] DE 10 2011 016 055 A1 discloses a front or rear body structure of a motor vehicle with a bumper crossmember connected to the front longitudinal members via deformation elements. The core of the application is the connection of the deformation elements to the longitudinal members. This is achieved using a bulkhead plate welded to the longitudinal members. To prepare the bulkhead plate for assembly, an inner recess is punched out of the bulkhead plate, and two sheet metal tabs are positioned at right angles to the bulkhead plate. The two sheet metal tabs are inserted into the longitudinal member and welded to the inner side walls of the longitudinal member. The bulkhead plate on the deformation element side is bolted to the bulkhead plate of the longitudinal member. Furthermore, the application discloses a bumper made of a U-profile, the U-profile being open towards the vehicle. In contrast, US 2009 / 0 085 362 A1 discloses a bumper whose U-profile is open to the outside, i.e., away from the vehicle.Here, deformation elements are connected to the bumper crossmember, but these elements do not extend into or onto the bumper crossmember and thus terminate at its inner boundary, i.e., at the point where the bumper crossmember extends towards the vehicle. The deformation element is therefore connected to the inside of the bumper crossmember at its end. Specifically, US 2009 / 0 085 362 A1 describes an octagonal deformation element that is arranged between the bumper crossmember and the longitudinal member and is assembled from two half-shells. Vertically oriented ribs are incorporated into the deformation element, enabling controlled deformation in a crash. Further deformation cups are known from DE 10 2006 044 384 A1, GB 2 299 551 A, and DE 10 2004 020 746 A1. DE 199 58 887 A1 describes a deformation element integrated into a U-shaped bumper crossmember, wherein the bumper crossmember, open to the vehicle, accommodates the deformation element.

[0004] The object of the invention is to provide a body shell structure of a motor vehicle with a cross member designed as a bumper and deformation elements that enables improved force absorption and force transmission in the event of a crash.

[0005] The problem is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims. The invention is applicable to bumper crossmembers designed as a U-profile and open either inwards or outwards when viewed in the direction of travel. The invention is based on the fact that an end-end connection of the deformation element, i.e., at the level of the first inward boundary or the second outward boundary of the bumper crossmember, is detrimental to crash performance.Furthermore, tests have shown that the interaction of the corrugations of the deformation elements with a special connection of the deformation elements to the bumper crossmember according to claim 1 is particularly effective, wherein the deformation element is designed as a closed hollow profile consisting of two half-shells, extending in the longitudinal direction of the vehicle and arranged symmetrically to a center line extending in the longitudinal direction of the vehicle, wherein the deformation element has side walls in each of which at least one corrugation is formed that runs perpendicular to the center line. The bumper crossmember, in turn, is designed as a profile with two horizontally extending profile walls and has a first boundary facing the deformation element when viewed in the longitudinal direction of the vehicle and a corresponding second boundary facing away from the deformation elements.The deformation element is connected to the bumper crossmember such that each deformation element extends longitudinally beyond the first boundary towards the second boundary, with each deformation element being spaced at least 5 mm from the second boundary. The distance is therefore at least 5 mm, and preferably at least 7 mm. The side walls of the deformation element are connected to each other via curved sections, such that the curved sections form an angle of 90 degrees and connect the respective perpendicular side walls. Each side wall has grooves that extend into the two curved sections adjacent to the side wall, but not into adjacent side walls.The groove thus extends across the entire width of the side wall and reaches into the curved section, ending there. This allows for a targeted, stepped folding effect.

[0006] Connecting the side wall of the deformation element to the profile wall of the bumper crossmember (also called the crossmember for short) is more advantageous in the longitudinal direction the greater the distance between the end of the deformation element and the first and second boundaries of the bumper crossmember. Beyond a minimum distance, the spacing becomes more favorable the greater the spacing. In one embodiment of the invention, the minimum distance is dimensioned such that the deformation element extends at least 7 mm beyond the first boundary. At least a portion of the deformation element terminates between the first and second boundaries, spaced apart from them. The length of this extension is therefore at least 7 mm, and preferably at least 10 mm.

[0007] In another practical embodiment, the deformation element, in the area of ​​its extension between the first and second boundaries, rests at least partially against the profile walls of the crossbeam. This enables particularly efficient force transmission from the crossbeam to the deformation element, as the crossbeam transfers the force into the deformation element very evenly. This results in a uniform load distribution across the corrugations.

[0008] Another advantageous embodiment provides that the opposing side walls of each deformation element extend beyond the first boundary and parallel to the profile walls of the crossbeam in the manner of a tongue, with the side walls adjacent to the opposing side walls being flush with an intermediate wall connecting the profile walls. Thus, not the entire deformation element extends beyond the first boundary onto or into the crossbeam, but only two opposing side walls. This is sufficient to introduce an optimal force impulse into the deformation element during a crash. Particularly advantageously, the side wall forms the tongue that creates the base of the deformation element's half-shell. The joining line of the two half-shells therefore runs along the side walls, which are flush with an intermediate wall of the crossbeam connecting the profile walls.

[0009] Furthermore, it is provided that the deformation elements are connected to the crossbeam via connecting welds. Specifically, the edges of the side walls are connected to the crossbeam via connecting welds. Thus, both the ends of the side walls of each deformation element, which extend beyond the first boundary and parallel to the profile walls of the crossbeam in a tongue-like manner, and the side walls that are flush with an intermediate wall of the crossbeam connecting the profile walls, are connected to the crossbeam. The ends of the side walls of each deformation element connected to the crossbeam, which extend beyond the first boundary and parallel to the profile walls of the crossbeam in a tongue-like manner, are also called tongue tips. The special connecting weld at the ends of the tongues is called a tongue weld to distinguish it from the other welds. The edges of the tongues run parallel to the first boundary of the side walls.In a particularly advantageous embodiment, the ends of the side walls are perpendicular to the vehicle's centerline. The connecting welds, and especially the tongue welds, thus run perpendicular to the centerline, just like the corrugations. The term "perpendicular" here also includes a manufacturing-related deviation of 5° from the vertical. Since the force from the cross member to the deformation element is primarily and predominantly transferred via the tongue welds during a crash, this promotes advantageous deformation behavior.

[0010] Preferably, the beads in adjacent side walls are arranged offset from one another in the longitudinal direction. This allows for a defined folding of the deformation element in the event of a crash and a particularly delicate, step-like folding of the deformation element. This enables the crash energy to be dissipated over many small steps, and force peaks are avoided. Another preferred embodiment provides that the beads in opposite side walls are arranged directly opposite each other in the longitudinal direction, at the same height. An opposing pair of beads is sufficient to enable folding at this point; a circumferential bead is actually disadvantageous, as the deformation element would be weakened too much at this point.

[0011] Furthermore, the connecting welds are designed to extend along the side walls of each deformation element and not into the curved sections. This ensures a sufficient connection between the deformation element and the cross member without adversely affecting the reproducibility of the crash behavior.

[0012] Furthermore, it is particularly advantageous that the two half-shells of each deformation element are connected to each other by a weld seam running parallel to the centerline. Specifically, the weld seam runs along the side walls, which are flush with an intermediate wall of the crossbeam that connects the profile walls. Thus, the weld seam does not run in the area of ​​the tongues.

[0013] The advantageous embodiments and further developments of the invention described above and / or described 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.

[0014] The invention and its advantageous embodiments and further developments, as well as their advantages, are explained in more detail below with reference to the exemplary embodiments shown schematically in the drawings.

[0015] They show: Fig. 1 schematically a shell structure as a platform for a motor vehicle body in a top view; Fig. 2 a front section of the in Fig. 1 shown shell structure; Fig. 3 a cut in the x-direction through a front section of the in Fig. 1 shown shell structure; Fig. 4 a crossbeam rotated by 180° opposite the one in Fig. 2 shown crossbeams in a front section of the shell structure; Fig. 5 a cross-sectional view through the in Fig. 2 or Fig. 4 deformation elements shown; Fig. 6 a partial excerpt from the in Fig. 4 section shown in a top view; and Fig. 7 a partial excerpt from the in Fig. Section 4 shown in a side view.

[0016] Fig. Figure 1 shows a top view of a body-in-white 1 of a motor vehicle, also called a platform. The platform contains the lower, load-bearing structures without the upper body panels and trim panels, also called the "hat." The body-in-white 1 has front and rear longitudinal members 2, which run in the x-direction, i.e., in the direction of travel of the motor vehicle. The longitudinal members 2 are extended in the x-direction to the end of the body-in-white 1, or body, by deformation elements 3, to which a cross member 4 is attached at the end as a bumper. The body-in-white 1 thus terminates with a cross member 4.

[0017] In Fig. Figure 2 shows a section of the body-in-white 1 as its front end, although a rear end may be identical. The shown end section of the longitudinal beam 2 is flanged to the deformation element 3 via bulkhead plates 5. Specifically, the bulkhead plate 5 belonging to the longitudinal beam 2 is connected to the bulkhead plate 5 associated with the deformation element 3 via fasteners not shown, e.g., bolts. The deformation element 3 is directly connected to the crossbeam 4, which acts as a bumper. The crossbeam 4 defines the front and / or rear boundary of the body-in-white 1 in the x-direction. In other words, the body-in-white 1 terminates at the crossbeam 4 in the x-direction, and the body-in-white 6, which ends at the bulkhead plate 5 of the longitudinal beam 2, is completed to form the body-in-white 1 via the deformation element 3 and the crossbeam 4.

[0018] The longitudinal beams 2 are, as shown Fig. As can be seen in Figure 1, the deformation elements 3 are arranged symmetrically within the structural frame 6 with respect to a center line 7 of the structural frame 6. Accordingly, the deformation elements 3 are also arranged symmetrically with respect to the center line 7, which represents the axis of symmetry of the structural frame 6 or the structural frame 1 in the direction of the longitudinal axis x. The crossbeam 4 is designed as a profile 8, and the crossbeam 4 essentially consists of a U-profile that transitions into two end flanges 9. The U-profile of the crossbeam 4 consists of two essentially horizontally arranged profile walls 10 and an intermediate wall 11 that connects the two profile walls 10. The intermediate wall 11 thus forms the base of the U-profile, which is completed by the two profile walls 10, each of which has an end flange 9 formed on it. As shown in Figure 1, the deformation elements 3 are arranged symmetrically with respect to the center line 7, which represents the axis of symmetry of the structural frame 6 or the structural frame 1 in the direction of the longitudinal axis x. Fig. As shown in Figure 2, the crossbeam 4, viewed in the direction of travel, begins at the end flanges 9, coming from the longitudinal beam 2, and ends at the partition wall 11. The crossbeam 4 is thus limited in its extension in the x-direction by the end flanges 9, which form a first boundary 12, and by the partition wall 11. Thus, the partition wall 11 closes, as shown in Fig. As shown in Figure 2, the structural frame 1 extends forward and / or backward and forms a second boundary 13, which terminates longitudinally with the structural frame 1. Fig. Figure 3 shows a section in the x-direction through the remaining structural shell 1 without the structural shell 6. The deformation element 3 is inserted into the crossbeam 4.

[0019] Crossbeam 4 can be installed in two variants, with crossbeam 4 being rotated 180 degrees in the second variant. Fig. Figure 2 shows the first variant, in which the partition wall 11 closes off the structural shell 1 at the front and / or rear. In the second variant, as shown in Fig. As shown in Figure 4, the crossbeam 4 is rotated by 180 degrees, and in this case, the end flanges 9 close off the vehicle or the body-in-white structure 1 at the front. In the Fig. In the embodiment shown in Figure 4, the partition wall 11 thus forms the first boundary 12, which closes off the crossbeam 4 towards the body shell 6. The end flanges 9 thus form the second boundary 13. By definition, the first boundary 12 is always directed towards the vehicle, i.e., towards the deformation element 3, while the second boundary 13 closes off to the outside in the x-direction or longitudinal direction with the body shell structure 1.

[0020] As in Fig. As can be seen in a section through a deformation element 3, the deformation elements 3 are formed from two half-shells 14. A first half-shell 14 is arranged horizontally, i.e., with an upwardly open U-profile, onto which a second half-shell 14 is placed, like a lid, with a U-profile now open downwards. The two half-shells 14 thus form a hollow profile 15 that runs longitudinally, i.e., in the x-direction, of the body-in-white structure 1. The two half-shells 14 of a deformation element 3 each form four side walls 16, with the legs of the U-profiles of the half-shells 14 each completing one side wall 16 of the deformation element 3. The side walls 16 are in turn connected to each other by curved sections 17, the curved sections 17 representing the radius of the hollow profile 15 and forming an angle of 90°.A half-shell 14 thus consists of a side wall 16 as a base, to which a curved section 17 is attached at each end. A portion of a side wall 16 is attached to the curved section 17, forming an angle of approximately 90° between the side wall 16 and the portion of a side wall 17 extending over the curved section 17. A groove 18 is formed in a side wall 16, extending into the adjacent curved sections 17 of the side wall 16. However, the groove 18 does not extend into the side walls 16 adjacent to the side wall 16, but terminates in the curved sections 17. The groove 18 is arranged perpendicular to the center line 7 of the structural frame 1. As shown in the... Fig. 6 and Fig. As shown in Figure 7, each side wall 16 has at least one groove 18. The grooves 18 in adjacent side walls are offset. The grooves 18 in opposite side walls 16 are arranged at the same height when viewed longitudinally. The two half-shells 14 are connected to each other by a weld 19, which runs along the joint between the two half-shells 14. The two side wall parts or halves are joined to form a complete side wall 16. Since the hollow profile 15 of the deformation element 3 runs in the longitudinal direction of the vehicle, the weld 19 also runs longitudinally, i.e., parallel to the center line 7. The half-shells 14 are attached to the body-in-white side, i.e., on the side of the longitudinal beam 2, as shown in Figure 7. Fig. As can be seen in section 3, a bulkhead plate 5 is welded on. The attachment of the deformation elements 3 to the crossbeam 4 is shown in the Fig. 6 and Fig. 7 shown, where the Fig. 6 and Fig. 7 each show only a section of the crossbeam 4 and thus only one deformation element 3. The Fig. 6 and Fig. 7 thus provide a detailed view of the Fig. 4 dar.

[0021] On the deformation element 3, two opposing side walls 16 are longer in the longitudinal direction, i.e., project beyond the other two side walls 16. These two opposing side walls 16 thus form a projection or tongue 20. This tongue 20 transitions into the curved sections 17 and terminates in the adjacent side wall 16. As defined above, as in Fig. As shown in Figure 4, the intermediate wall 11 of the crossbeam 4 forms a first boundary 12. The tongue 20 of the deformation element 3 is designed such that the tongue 20, or rather the upper and lower side walls 16 of the hollow profile 15 of the deformation element 3, extends beyond the first boundary 12 onto the crossbeam 4. In other words, the tongue 20, or rather the upper and lower side walls 16, projects beyond the intermediate wall 11 of the crossbeam 4 in the x-direction towards the second boundary 13, which is equivalent to the end of the structural frame 1. The tongue length, i.e., the length L of the tongue 20, is at least 7 mm from the intermediate wall 11. The tongue 20 does not extend to the second boundary 13 and does not touch the end flange 9 of the crossbeam 4, but maintains a visible distance A from the end flange 9, which is at least 5 mm. This promotes an effective distribution of forces onto the deformation element 3 in the event of a crash.

[0022] In contrast, the lateral side walls 16 of the deformation elements 3 converge on the intermediate wall 11 and terminate in contact with it. The deformation element 3 is welded along its lateral side walls 16 to the intermediate wall 11 of the crossbeam 4 along a butt joint 21 via a connecting weld 22. As already mentioned, the upper and lower side walls 16, i.e., those spanning in the xy-plane, form a tongue 20 that projects beyond the lateral side walls 16 in the x-direction. The tongue 20 runs at least partially parallel to the profile walls 10 of the crossbeam 4 and is in contact with them at least partially. In other words, the tongue 20 rests against the profile wall 10 of the crossbeam, at least at its end, and is welded to it via a tongue weld 23. The tongue weld 23 runs parallel to at least one groove 18 of the deformation element 3.

[0023] In the Fig. In the alternative embodiment shown, the end flanges 9 form a first boundary 12 that closes off the crossbeam 4 towards the structural frame 6. The partition wall 11 thus forms a second boundary 13 that closes off the structural frame 1 in the x-direction or longitudinal direction to the outside. As in the previous example according to Fig. 4, Fig. 6 and Fig.7 The two opposing side walls 16 of the deformation element 3, lying in the xy-plane, form a tongue 20. The tongue 20 of the deformation element 3 is designed such that the upper and lower side walls 16 of the hollow profile 15 of the deformation element 3, lying in the xy-plane, extend beyond the first boundary 12 into the crossbeam 4, parallel to the profile wall 10 and at least partially abutting this profile wall 10 of the crossbeam 4. In other words, the upper and lower side walls 16 project beyond the end flanges 9 of the crossbeam 4 in the x-direction towards the second boundary 13, and the tongue 20 of the side wall 16 extends into the U-profile of the crossbeam 4. However, the tongue 20 does not extend to the second boundary 13 and does not touch the intermediate wall 11 of the crossbeam 4, but has a visible distance A to the intermediate wall 11, which is at least 5 mm.This promotes an effective distribution of forces onto the deformation element 3 in the event of a crash. The end of the tongue 20 is welded to the profile wall 10 of the crossbeam 4 via a connecting weld 22. Reference symbol list 1. Shell structure 2 longitudinal beams 3 Deformation element 4 crossbeams 5 bulkhead plate 6 Shell construction 7 Center line 8 Profile 9 End flange 10 profile wall 11 Partition wall 12 First Limit 13 Second Limit 14 half-shell 15 Hollow profile 16 side wall 17 Curved Section 18 groove 19 weld seam 20 Tongue 21 Impact edge 22 Joining weld 23 Tongue weld A distance L tongue length

Claims

[1] Body shell (1) of a motor vehicle with a cross member (4) designed as a bumper, which is connected to the body shell (6) via deformation elements (3), wherein the deformation elements (3) are designed as closed hollow profiles (15) extending in the longitudinal direction of the motor vehicle and are arranged symmetrically with respect to a center line (7) extending in the longitudinal direction of the motor vehicle, wherein each deformation element (3) has side walls (16) in which at least one groove (18) is formed which runs perpendicular to the center line (7), wherein the cross member (4) is designed as a profile with two horizontally extending profile walls (10) and has a first boundary (12) facing the deformation elements (3) when viewed in the longitudinal direction of the motor vehicle and a corresponding second boundary (13) facing away from the deformation elements (3),wherein each deformation element (3) consists of two half-shells (14) and each deformation element (3) extends longitudinally beyond the first boundary (12) in the direction of the second boundary (13), wherein each deformation element (3) is spaced at least 5 mm from the second boundary (13), wherein the side walls (16) of each deformation element (3) are connected to each other via curved sections (17) such that the curved sections (17) form an angle of 90 degrees and connect the respective perpendicular side walls (16) to each other, wherein a groove (18) of a side wall (16) extends into the two curved sections (17) but not into adjacent side walls (16), wherein the deformation elements (3) are connected to the crossbeam (4) via connecting welds (22), , characterized by, that the connecting welds (22) extend along the side walls (16) of each deformation element (3) and not into the curved sections (17). [2] Body structure of a motor vehicle according to claim 1, characterized by that each deformation element (3) extends at least 7 mm beyond the first boundary (12). [3] Body shell of a motor vehicle according to claim 1 or claim 2, characterized by , that each deformation element (3) in the area of ​​its extension between the first boundary (12) and the second boundary (13) bears at least sectionally against the profile walls (10) of the crossbeam (4). [4] Body shell of a motor vehicle according to any of the preceding claims, characterized by, that the opposite side walls (16) of each deformation element (3) extend over the first boundary (12) and parallel to the profile walls (10) of the crossbeam (4) in the manner of a tongue (20), wherein the side walls (16) adjacent to the opposite side walls (16) terminate flush with an intermediate wall (11) connecting the profile walls (10). [5] Body shell of a motor vehicle according to any of the preceding claims, characterized by , that the corrugations (18) in adjacent side walls (16) are arranged offset from each other in the longitudinal direction. [6] Body shell of a motor vehicle according to any of the preceding claims, characterized by , that the corrugations (18) in opposite side walls (16) are arranged directly opposite each other when viewed in the longitudinal direction. [7] Body shell of a motor vehicle according to any of the preceding claims, characterized by, that the two half-shells (14) of each deformation element (3) are connected to each other via a weld (19).

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