CN108791524B

CN108791524B - Underbody structure for a two-track vehicle

Info

Publication number: CN108791524B
Application number: CN201810425202.9A
Authority: CN
Inventors: R.西格蒙德; T.M.党; S.洛曼
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2017-05-05
Filing date: 2018-05-07
Publication date: 2020-10-20
Anticipated expiration: 2038-05-07
Also published as: CN108791524A; DE102017207623B3

Abstract

The invention relates to an underbody structure for a two-track vehicle, comprising a transverse beam arrangement (36) in the rear vehicle body, wherein the transverse beam arrangement (36) is formed by a wheel housing transverse beam (19) which is arranged above the floor and extends between the rear wheel housings (5) and a rear transverse beam (37) which is arranged directly adjacent to the wheel housing transverse beam in the longitudinal direction (x) of the vehicle forward, wherein the rear transverse beam (37) is formed by a cross-beam plate (39) which is shell-shaped in cross section and has an open hollow cross section, wherein the cross-beam plate (39) is connected to the underside of the floor at a front and rear joining point (F1, F2) in the longitudinal direction (x) of the vehicle while forming a closed hollow cross section (47).

Description

Underbody structure for a two-track vehicle

Technical Field

The invention relates to an underbody structure for a two-track vehicle according to the preamble of claim 1.

Background

During driving operation, in particular during cornering, the rear side of the vehicle body is subjected to a torque directed about the vehicle longitudinal center axis, wherein the rear side of the vehicle body is twisted relative to the front side of the vehicle body. In order to increase the torsional rigidity, it is known to reinforce the interior corner region between the rear wheel house and the floor panel on the luggage compartment side with a corner reinforcement. To further increase the torsional rigidity, two opposite corner reinforcements can be connected to the wheel house cross member.

This underbody structure has a cross member device in the vehicle rear portion, which is constituted by a wheel house cross member and a rear cross member. The wheel house cross member is arranged above on the floor panel, while the rear cross member is directly adjacent to the wheel house cross member in the longitudinal direction of the vehicle and is designed in a shell-type configuration, i.e. is made of a cross member plate which is shell-shaped in cross section and has an open hollow cross section, said cross member plate being connected to the floor panel bottom side in the joining position while forming a closed hollow cross section. The cross beam panels may be joined at the joint locations by spot welding. In the case of spot welding, the spot welding tongs in particular require passages on both sides in order to reach the joining point of the rear cross member. However, depending on the positioning of the wheel housing cross member arranged on the upper side, such a tool access of the spot welding pliers to the joining point of the rear cross member can be obstructed or can be completely covered. In this case, a limitation is formed when assembling the vehicle body bottom structure.

DE 10348354 a1 discloses a vehicle underbody structure in which a wheel house cross member is associated for increasing torsional rigidity, said cross member being mounted on two rear wheel houses. DE 10206476 a1 discloses a rear reinforcement structure in which the wheel house cross member has a closed cross-sectional cross section.

Disclosure of Invention

The invention is based on the object of providing a body bottom structure for a two-track vehicle, which allows more degrees of freedom in assembly than in the prior art.

The invention is based on the fact that the wheel house cross member and the rear cross member in the conventional solution are realized in a shell-type construction, i.e. as a sheet element which takes up a relatively large construction space and is produced in a deep-drawing process, so that there is the risk that the wheel house cross member at least partially covers the joining location of the rear cross member which is connected to the floor on the underside when the underbody structure is installed. Against this background, the wheel house cross member according to the characterizing part of claim 1 is designed as a hollow profile part which is closed in cross section over the circumference. The wheel house cross member can preferably have a rectangular cross section with a profile base connected to the floor in a force-transmitting manner, and a profile cover and two profile side walls. The wheel house cross member may also be disposed behind the engagement location at the rear of the rear cross member with a net longitudinal offset. In this case, the joining position of the rear cross member is arranged in the vehicle height direction upward in an uncovered manner with respect to the wheel house cross member, so that a tool passage of the spot welding tongs without interfering shape is ensured.

With the aid of the invention, the rigidity target of the body structure of the vehicle item is achieved by the wheel house cross member in the region behind the second seat row of the vehicle interior space. The wheel house cross-beam connects two corner reinforcement plates, which are located on the left and right side of the wheel house. The wheel house cross member is designed as a closed profile and ends on the wheel house in the transition area to the corner reinforcement plate. The wheel house beams may be joined by spot welding through alternating through holes (i.e., tool access holes) in the wheel house beams. The closed cross section makes efficient use of the available installation space in terms of satisfying the function. Here, no demolding draft has to be taken into account and no point flange for the base part is required. The closed profile of the wheel house cross member can also compensate for hollow positions which are limited by installation space, for example in the region of the spare groove cover. The closed wheel house cross member hollow section also achieves a local reduction of the contact surface without a significant reduction in function and without an increase in wall thickness due to the required increase and without the need for adjustment of surrounding components. The cross beam is bonded in the contact area with the floor.

The closed wheel house cross member hollow section also achieves a local reduction of the contact surface without a significant reduction in function and without an increase in wall thickness due to the required increase and without the need for adjustment of surrounding components.

Alternatively, the wheel house cross member can also be designed with a flange. Laser welding seams can thereby be avoided. The already planned double-plate welding points in the body-in-white can be used for connecting the cross members by means of triple-plate welding points. Furthermore, the beams may also be connected to themselves around by alternating flange trims.

By dividing the corner reinforcement plate into a front and a rear shell part, the wheel house cross member can be inserted into the shell construction of the corner reinforcement plate by means of conventional joining techniques (i.e. spot welding). In order to ensure spot weldability, the holes can be arranged in the closed profile in a variable and offset manner. By the shape of the transition portion, the width of the assembly can be corrected at any time according to the surrounding environment.

Another aspect of the invention is set forth below: the wheel house cross member can be connected to the floor in any manner that allows force transmission. In the case of a closed profile cross section of the wheel housing transverse member, a passage of the spot welding tongs without interfering contours may not be ensured. In this case, it is preferred that the wheel house cross member is glued to the floor plate with its profile base.

In order to increase the rigidity of the connection, the profile base of the wheel house cross member can be formed, together with the floor plate and the rear edge flange of the shell-shaped cross member plate, as a three-layer structure for reinforcement of the component.

In one technical embodiment, the floor panel may be constituted by a front floor panel member and a rear floor panel member in the vehicle longitudinal direction. The front floor part can be designed with a mounting section for a rear seat of the vehicle, while the rear floor part together with the rear wheel housing defines a storage space on the rear side of the vehicle.

The two floor elements can be flanged to each other (preferably by spot welding) on their mutually facing joining flanges. The flange connection is preferably positioned directly at the joining location at the rear of the rear cross member. Furthermore, the two joining flanges of the floor panel can form a rigid three-layer structure with the rear edge flange of the shell-shaped cross-beam panel.

Depending on the joining sequence, the joining flange of the front floor part can be arranged in the flange connection described above in the vehicle interior, i.e. on the upper side. In this case, it is advantageous from a mounting standpoint for the wheel house cross member to be arranged behind the rearwardly directed cut edge of the joining flange of the front panel with a longitudinal offset.

In terms of the intact torsional rigidity of the rear body, it is advantageous if the inner corner region between the floor panel and the rear wheel housing is reinforced by a corner reinforcement plate. Two corner reinforcement plates which are arranged opposite one another in the transverse direction of the vehicle can be connected in a force-transmitting manner by means of a wheel house cross member. Each corner reinforcement plate has a connecting contour with a through-opening, into which the wheel house cross member projects at the end. Preferably, the wheel house cross member can be in a spot-welded connection with the corner reinforcement plate.

In order to ensure that spot welding is possible, it is preferred if the corner gusset elements are designed in two parts, specifically consisting of a front shell and a rear shell in the longitudinal direction of the vehicle. The two sheet metal shells can each define a passage opening in the assembled state with a partial opening edge.

The assembly of the corner reinforcement panel of this two-piece design with the wheel house cross member can be accomplished in the following joining sequence: in a first joining step, the first profile side wall and the profile cover are spot-welded to the partial connecting contour of the first sheet metal shell at a first spot welding location. In a second joining step, the second profile side wall and the profile bottom are then spot welded to the partial connecting contour of the second shell of the corner reinforcing plate. The first and second spot welding positions are offset from each other as viewed in the lateral direction of the vehicle. Furthermore, the two profile side walls have tool passage openings which realize a tool passage of the spot welding tongs to the first and second spot welding positions without interfering contour.

In a special embodiment, the wheel house cross member can be produced from a flat blank by means of a roll forming process. In this case, the wheel house cross member can be extended with outwardly projecting edge flanges at the mutually facing plate edges. The (two) panel edges may be provided as flange connections (e.g. by spot welding) and may also be connected to the base panel by another joining location.

Drawings

Embodiments of the present invention are described below with reference to the drawings. In the drawings:

fig. 1 shows a partial cross-sectional view of a two-track vehicle in a side view;

FIG. 2 shows an underbody structure in the rear body region of the vehicle;

FIGS. 3 to 5 respectively show sectional views along the sectional plane A-A in FIG. 2;

FIG. 6 illustrates the attachment of the wheel house cross member to the corner reinforcement panel;

fig. 7 and 8 each show a view in accordance with fig. 6, illustrating the sequence of engagement for attaching the wheel house cross member to the corner reinforcement panel.

Detailed Description

Fig. 1 shows a rear-end underbody structure for a vehicle, wherein the rear-end storage space 1 is delimited by a rear floor panel 13 and, in the transverse direction y of the vehicle, outwardly by a rear wheel house 7, wherein fig. 1 only shows a wheel house panel 5. In fig. 2, the wheel housing panel 5 has a circumferential wall 9 extending at intervals around the rear wheel 7, the circumferential wall 9 transitioning in the transverse direction y of the vehicle inward to a vertical side wall 11 in the vehicle interior. The side walls 11 are connected at the bottom side, for example by welding points, to a rear floor part 13. As further shown in fig. 2, the inner corner region between the side wall 11 of the wheel house panel 5 and the rear floor panel 13 is reinforced with a wheel house beam reinforcement 15.

In fig. 2, the wheel house cross member reinforcement 15 has a wheel house-side, shell-shaped corner reinforcement plate 17, which corner reinforcement plate 17 merges into a transversely running wheel house cross member 19. The wheel house cross member 19 is not produced in the manner of a shell construction, but rather is constructed as a hollow profile part which is closed circumferentially in cross section, specifically according to fig. 3 to 5, with a profile base 21, a profile cover 23 and a front profile side wall 25 and a rear profile side wall 27.

In fig. 3, the rear floor part 13 extends in the vehicle longitudinal direction x forward by means of a front floor part 29, on which front floor part 29 a mounting section 31 for a rear seat of the vehicle, not shown in detail, is formed. The two

floor elements

13,29 are in spot-welded connection on their mutually facing joining

flanges

33, 35.

The wheel house cross member 19 and the rear cross member 37 together form a cross member arrangement 36 (fig. 1). In the transverse member arrangement 36, the rear transverse member 37 is arranged directly adjacent to the wheel house transverse member 19 in the vehicle longitudinal direction x in the forward direction and engages on the floor in a shell-type configuration. The shell-type construction is illustrated by the cross-sectional shell-shaped cross-beam plate 39, which is connected with its front and

rear edge flanges

41, 43 to the underside of the front floor plate 29 at the front and rear joining points F1, F2. The connection is made by spot welding by means of spot welding clamps, not shown, which require access to the free channels on both sides of the joining points F1, F2. The bottom cross member plate 39 defines a closed cavity 47 in cross section together with a cross member profile 45, which cross member profile 45 is formed in the front cross member plate 29.

As shown in fig. 3, the two

joint flanges

33, 35 of the

floor panels

13,29 together with the rear edge flange 43 of the cross-beam panel 39 form a rigid three-layer structure. In the same way, the profile base 21 of the wheel house cross member 19 can also form a rigid three-layer structure together with the rear floor plate 13 and the rear edge flange 43 of the cross plate 39. In fig. 3, the wheel house cross member 19 is arranged behind the rear joining point F2 with a clear longitudinal offset Δ x, in order to ensure an unobstructed passage of the spot welding pliers into the joining point F2. Furthermore, the cut edge 32 of the engagement flange 33 of the front plate member 29 is also spaced from the wheel house cross member 19 by a net longitudinal offset. In the joining position F2, the two joining

flanges

33, 35 of the

floor panels

13,29 and the rear edge flange 43 of the lower cross-beam panel 39 are connected to each other by spot welding. The wheel house cross member 19 is in turn connected to the rear floor plate 13 by means of an adhesive connection 49, while the rear edge flange 43 of the cross member plate 39 is also spot welded to the joining flange 35 of the rear floor plate 13.

The closed profile of the wheel house cross member 19 can also compensate for a cavity position 48 which is limited by installation space, for example in the region of the spare groove cover, as shown, for example, in fig. 4 and 5. The wheel house cross member 19 is therefore connected to the floor plate only with a locally strongly reduced contact surface in the region of the cavity point 48, without a significant functional impairment.

Fig. 5 shows a wheel house cross member 19 according to a second exemplary embodiment. The wheel house cross member 19 is accordingly produced from a flat blank by means of a roll forming process. In fig. 5, the front profile side wall 25 is provided at its bottom edge with an outwardly bent edge collar 51, while the profile base 21 extends with a further edge collar 53 in an outwardly flat manner. The two

edge flanges

51,53 are connected to each other at a joining position F2. Furthermore, the two

edge flanges

51,53 of the wheel house cross member 19 can have alternating flange sections in the flange extension in the transverse direction y of the vehicle. In this case, either only the lower flange 53 of the wheel house cross member 19 or only the upper flange 51 of the wheel house cross member 19 is spot welded to the floor.

Fig. 6 shows the corner reinforcement plate 17, the corner reinforcement plate 17 having a connecting contour 55 with a through opening 57, the wheel house cross member 19 protruding with its end face into the through opening 57. The wheel house cross member 19 is in spot-welded connection with the connecting contour 55. In order to ensure such spot weldability, the corner reinforcement panel 17 is formed in two parts from a front panel shell 59 in the vehicle longitudinal direction x and a rear panel shell 61 in the vehicle longitudinal direction. Each of the two

plate shells

59,61 defines a through-opening 57 with a partially open edge. In the first spot welding position P1, the front profile side wall 25 and possibly the profile cover 23 are spot welded to a partial connecting profile of the front plate shell 59. In the second spot welding position P2, the rear profile side wall 27 and possibly the profile cover 23 are spot welded to a partial connecting profile of the rear plate shell 61. Furthermore, both

profile side walls

25,27 have tool passage openings 63 which provide a tool passage of the spot welding tongs to the first and second spot welding positions P1, P2 without interfering contours. The tool passage openings 63 are offset relative to each other in the vehicle transverse direction y. Likewise, the first and second spot welding positions P1, P2 are also offset relative to each other in the vehicle transverse direction y.

In the joining sequence, in a first joining step (fig. 7), the front profile side wall 25 is spot-welded in a first spot welding process I with a partial connecting contour of the front plate shell 59, specifically in the case of the formation of a first spot welding position P1. In a second joining step (fig. 8), the rear profile side wall 27 and the profile cover 23 are then spot-welded to the partial connecting contour of the rear plate shell 61, specifically in the case of a second spot welding position P2.

List of reference numerals

1 storage space

5 wheel cover plate

7 rear wheel

9 peripheral wall

11 vertical side wall

13 rear floor element

15 wheel house transverse reinforcement

17-corner reinforcing plate

19 wheel house beam

21 section bar bottom

23 section bar cover

25. 27 section side wall

29 front floor element

31 mounting section

33. 35 joining flange of floor member

36 crossbeam device

37 rear cross member

39 Cross beam plate

41. 43 edge flange

F1, F2 front and rear joining position

45 beam profile

47 closed cavity

48 cavity position

49 adhesive joint

51. 53 edge flange

55 connecting profile

57 through hole

59 front panel

61 rear panel shell

63 tool opening

Δ x net longitudinal offset

P1, P2 spot welding position

F1, F2 engaged position

Claims

1. Underbody structure for a two-track vehicle, having a transverse beam arrangement (36) in the rear vehicle body, the transverse beam arrangement (36) being formed by a wheel house transverse beam (19) which is arranged above a floor and extends between the rear wheel houses (5) and by a rear transverse beam (37) which is directly adjacent to the wheel house transverse beam in the vehicle longitudinal direction (x) forward, the rear transverse beam (37) being formed by a cross-sectionally shell-shaped transverse beam plate (39) having an open hollow cross section, the transverse beam plate (39) being connected to the floor underside in a front and rear joining position (F1, F2) in the vehicle longitudinal direction (x) while forming a closed hollow cross section (47), characterized in that the wheel house transverse beam (19) is formed as a hollow profile which is closed over the circumference in cross section and the profile base (21) of which is connected to the floor in a force-transmittable manner, and the wheel house cross member (19) is arranged behind the rear engagement position (F2) of the rear cross member (37) by a net longitudinal offset (Δ x) such that the rear engagement position (F2) is uncovered in the vehicle height direction (z) relative to the wheel house cross member (19).

2. The underbody structure of claim 1, characterized in that the wheel house cross member (19) is glued to the floor by means of its profile bottom (31).

3. The underbody structure of claim 1 or 2, characterized in that the profile foot (21) of the wheel house cross member (19), the floor and the rear edge flange (43) of the shell-shaped cross member panel (39) form a three-layer structure.

4. The underbody structure of claim 1, characterized in that the floor panel is formed by a front floor panel part (29) and a rear floor panel part (13) in the vehicle longitudinal direction (x), the front floor panel part (29) having a mounting section (31) for a rear seat of the vehicle, the rear floor panel part (13) and the rear wheel house (5) together defining a storage space (1) on the vehicle rear side, and the two floor panels (13,29) are flanged to each other on their mutually facing joint flanges, i.e. in a joint position (F2) at the rear of the rear cross member (37), and the two joint flanges of the two floor panels (13,29) form a three-layer structure with the rear edge flange (43) of the shell-shaped cross member panel (39).

5. The underbody structure of claim 4, characterized in that the joining flange (33) of the front floor element (29) is arranged in the flange connection in the vehicle interior, i.e. on the upper side, and the rearwardly directed cutting edge (32) of the joining flange (33) of the front panel element (29) is spaced apart from the wheelhouse cross member (19) by a further net longitudinal offset.

6. The vehicle body bottom structure according to claim 4, wherein the joining positions of the front and rear portions of the rear cross member (37) are spot welding positions, and the flange connection between the joining flanges of the two floor members (13,29) is also spot welding.

7. The underbody structure of claim 1, characterized in that a corner reinforcement panel (17) is arranged in an inner corner region formed between the floor and the rear wheel house (5), and the corner reinforcement panel (17) has a connecting contour (55) with a through opening (57), into which the wheel house cross member (19) projects, and the wheel house cross member (19) is in spot-welded connection with the corner reinforcement panel (17).

8. The underbody structure of claim 7, wherein the corner reinforcing panel (17) is formed in two parts from a front shell (59) and a rear shell (61) in the longitudinal direction (x) of the vehicle, in order to ensure spot weldability, wherein each shell (59,61) defines the through-hole (57) with a part of the opening edge.

9. The underbody structure of claim 1, characterized in that the wheel house cross member (19) is formed as a rectangular profile from the profile bottom (21), the profile cover (23) and the front profile side wall (25) and the rear profile side wall (27).

10. The underbody structure of claim 9, characterized in that in a first spot welding position (P1) the first profile side wall (25) and part of the connecting profile of the profile cover (23) with the first panel shell (59) form a spot weld, in a second spot welding position (P2) the second profile side wall (27) and part of the connecting profile of the profile cover (23) with the second panel shell (61) form a spot weld, and in that in both profile side walls (25,27) a tool passage opening (63) is constructed, which tool passage opening (63) enables tool passage of a spot welding pliers to the first and second spot welding positions (P1, P2).

11. The underbody structure of claim 1, characterized in that the wheel house cross member (19) is produced from a sheet metal blank by a roll forming process and/or that the wheel house cross member (19) is extended at the mutually facing edges of the sheet metal blank by outwardly projecting edge flanges (51,53) which are flanged to each other and/or to the floor.