AUTOMOTIVE BODY SHELL

Abstract

An automobile body shell comprises a composite underbody component (20) being made of carbon-fibre-reinforced plastic material (CFRP) and rocker panels (30) connected to the composite underbody (20) component at outer sides thereof. The rocker panels (30) are made of metallic material. Thereby the automobile body shell can be optimized namely in obtaining a stiff passenger cell (10) in combination with rocker panels (30) which can more effectively deform under impact forces.

Claims

1. An automobile body shell comprising: a. an underbody component being made of fibre-reinforced plastic material, and b. at least one rocker panel interconnected to the underbody component at an outer side thereof, extending in a longitudinal direction (x) of the underbody component, wherein c. the at least one rocker panel is in a transversal direction (y) designed in a more deformable manner compared to the underbody component, such that impact energy occurring in the lateral direction (y) is absorbed by deformation of the rocker panel.

2. The automobile body shell according to claim 1, wherein the composite underbody component comprises at least one crossmember extending in the transversal direction (y).

3. The automobile body shell according to claim 2, wherein the at least one crossmember is mechanically interconnected to the at least one rocker panel.

4. The automobile body shell according to claim 1, wherein the fibre-reinforced plastic material of the underbody component comprises carbon fibres and/or Kevlar fibres and/or glass fibres and/or metallic fibres and/or natural fibres.

5. The automobile body shell according to claim 1, wherein the at least one rocker panel comprises an outer shell.

6. The automobile body shell according to claim 5, wherein the outer shell is at least partially made of ductile sheet metal and/or composite material.

7. The automobile body shell according to claim 6, wherein the outer shell comprises several layers of the sheet metal and/or the composite material.

8. The automobile body shell according to claim 5, wherein the outer shell of the at least one rocker panel has in the transversal direction (y) an in principle a C-shaped cross-section.

9. The automobile body shell according to claim 5, wherein the outer shell of the at least one rocker panel has in the transversal direction (y) a multi-cell cross-section.

10. The automobile body shell according to claim 5, wherein the outer shell of the at least one rocker panel comprises at least one drainage.

11. The automobile body shell according to claim 1, wherein the at least one rocker panel comprises foam material and/or honeycomb material for absorbing impact energy during impact.

12. The automobile body shell according to claim 11, wherein the foam material and/or the honeycomb material is arranged between the underbody component and an outer shell of the at least one rocker panel.

13. The automobile body shell according to claim 12, wherein the foam material and/or the honeycomb material forms at least one support between a side structure of the underbody component and the outer shell of the at least one rocker panel (30).

14. The automobile body shell according to claim 1, wherein the composite underbody component essentially extents over the area of the passenger cell.

15. The automobile body shell according to claim 1, wherein the underbody component comprises at least one tunnel extending in the lengthwise direction (x).

16. The automobile body shell according to claim 1, wherein the composite underbody component has at least one trough shaped structure for receiving a battery pack of an electric drive.

17. The automobile body shell according to claim 1, wherein a layer of insulating material is provided between connection faces of the underbody component and the at least one rocker panels at which the connection faces of the composite underbody component and the at least one rocker panels are connected to each other, the fibre-reinforced plastic material comprises carbon-fibre-reinforced plastic material, and the layer of insulating material provides a galvanic isolation between the carbon-fibre-reinforced plastic material of the composite underbody component and a metallic material of the at least one rocker panels.

18. The automobile body shell according to claim 17, wherein the layer providing the galvanic isolation between the carbon-fibre-reinforced plastic material of the composite underbody component and the metallic material of the at least one rocker panels is an adhesive material which provides an adhesive bond between the composite underbody component and the at least one rocker panels.

19. The automobile body shell according to claim 18, wherein the composite underbody component and the at least one rocker panels are also mechanically connected to each other.

20. The automobile body shell according to claim 1, wherein the reinforced plastic material used for the composite underbody component withstands a cathodic dip painting process with a temperature of least 190 C. during at least 30 min.

21. A method for producing an automobile body shell, comprising the steps of: a. providing a underbody component made from fibre-reinforced plastic material by a RTM procedure having first connection faces; b. providing rocker panels made from a metallic material having second connection faces; c. applying a layer of an adhesive material to at least one of the first or second connection faces; d. bringing the first connection faces of the composite underbody component in contact with the second connection faces of the rocker panels; e. at least temporarily fixing the first and second connection faces in contact with each other by mechanical fixation means; and f. causing the adhesive material to develop an adhesive bond in a cathodic dip painting process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The herein described invention will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the invention described in the appended claims. The drawings are showing:

[0031] FIG. 1 a perspective view of an automotive body shell comprising a composite underbody component and rocker panels according to the present invention.

[0032] FIG. 2 a perspective view on the upper side of the composite underbody component with the rocker panels and some other parts connected therewith;

[0033] FIG. 3 a perspective view on the lower side of the composite underbody component with the rocker panels and some other parts connected therewith.

[0034] FIG. 4 a plan view on the composite underbody component with the rocker panels and some other parts connected therewith.

[0035] FIG. 5 a sectional view (D-D in FIG. 4)

[0036] FIG. 6 shows detail E of FIG. 5.

[0037] FIG. 7 an exploded perspective view of the composite underbody component, the rocker panels and some other parts separately.

DESCRIPTION OF THE EMBODIMENTS

[0038] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0039] Referring now to the accompanying drawings wherein like reference numerals denote like elements through the various views, one exemplary embodiment of an automobile body shell is shown in FIG. 1 having a passenger cell 10. The automobile body shell according to the invention includes an underbody component 20 and two rocker panels 30 laterally interconnected thereto.

[0040] The underbody component 20 is in the shown variation symmetrically shaped with regard to a plane (extending in the x-z-directions) along centre line CL and includes a tunnel 21 in the form of an inverted channel longitudinally extending between a front end wall structure 22 and a rear end wall structure 23. If present, the middle tunnel 21 can be foreseen to receive a drive shaft. Alternatively or in addition, the tunnel 21 can be foreseen to receive a battery, e.g. in case of an electric drive.

[0041] A first and a second cross member 24, 25 extend transversely between the tunnel 21 and lateral side wall structures 26 to which the rocker panels 30 are interconnected as described herein. The first and the second crossmembers 24, 25 are having an open cross-section facing downward such that they can easily be demolded during production. Other shapes are possible. The first and the second crossmembers 24, 25 serve among others as reinforcing rails in the transverse direction avoiding unwanted deformation (collapse) of the underbody component e.g. during side impact. The underbody component furthermore comprises a bottom 35 which extends between the side wall structures 26 and if present, the crossmembers 24, 25, respectively the tunnel 21, if present.

[0042] Interconnected to the side wall structures 26 are rocker panels 30, commonly also referred to a rocker outer, which extend longitudinally (x-direction, respectively driving direction) almost in parallel to the tunnel 21 along the side walls 26. In the drawings further parts are visible, which are interconnected with the underbody component 20. Among others, two front end side rails 40, a bulkhead 50, at least one faceplate 60, a rear seat cross member 70, and a rear seatback member 80 are visible. As it can be seen the front end side rails 40 extend into the bottom 35 of the underbody component 20. At least one faceplate 60 can be foreseen to form a closed box-like structure to increase stability and stiffness of the overall structure 20.

[0043] As can be seen from FIG. 1, the underbody component 20 of the shown variation essentially extents over the area of the passenger cell 10 in the horizontal direction but does not essentially extend beyond the area of the passenger cell 10 in this direction. In the vertical direction the composite underbody component 20 does not essentially extend beyond the height of the middle tunnel. Depending on the field of application the length L of the composite underbody component 20 in the x-direction is typically between 2000-2500 mm, whereas the width W in the y-direction is between 1300-1600 mm. Its height H is between 150-500 mm. Other dimensions are possible.

[0044] The composite underbody component 20 is preferably made of one or several composite materials, e.g. carbon-fibre-reinforced plastic material (CFRP), and is produced by a RTM process. For easy production it should be kept free of cavities and undercuts which can not be demolded. Thereby it can be molded as a monolithic piece with high precision in one step in a two-part or at least a three-part mold. If required, one or several inserts can be placed in the mold before curing of the composite material.

[0045] Rocker panels 30 as shown here are made of a ductile material by deep drawing, e.g. by deep drawing of sheet metal such as steel and/or aluminium. The sheet metal of the rocker panels 30 is forming a shell 33 having an in principle C-shaped cross section. If required, patches or tapes (both not shown in detail) of composite material can be applied locally or over the whole shell 33 for specific reinforcement. This may as well be the case for the other mentioned parts 40-90.

[0046] The underbody component 20 is provided, at least in the area of its side wall structures 26 but preferably all around its circumference with one or several first connection faces 27 arranged in sequence or parallel to each other. Corresponding second connection faces 31 are provided at least the rocker panels 30. FIG. 5 and FIG. 6 in more detail show how connection faces 27 and 31 are connected to each other. Between the connection faces 27, 31 there is provided a layer 28 as this is shown in FIG. 5 and in more detail in FIG. 6. A layer 28 provides a galvanic isolation between the carbon-fibre-reinforced plastic material of the composite underbody component 20 and the metallic material of the rocker panels 30. It may have a thickness of 3/10- 7/10 mm. Layer 28 is an adhesive layer in addition which provides an adhesive bond between the respective connection faces 27 and 31. At least temporary fixation is achieved by mechanical fixation means such as rivet 29 shown in FIGS. 5 and 6 are provided at distinct locations to at least temporarily connect the underbody component 20 and the rocker panels 30 prior to the adhesive of layer obtaining its final bonding strength by temperature curing for example.

[0047] For compensating different thermal extension e.g. of the carbon-fibre-reinforced plastic material of the underbody component 20 on the one hand and metallic material of the rocker panels 30 on the other hand, the rocker panels may be provided with beads 32. The beads 32 can be arranged between the mechanical connection points, if present. With regard to the interconnection between the underbody component 20 and the other parts 40-90, that what has been described with respect to the galvanic isolation, the adhesive bonding, the at least provisional mechanical connection and the thermal extension, may also apply to such other parts.

[0048] FIG. 7 is showing the underbody component 20 and the rocker panels 30 according to the FIGS. 1 through 6, as well as other parts in an exploded manner in a perspective view. Assembly directions are schematically indicated by dotted lines). The underbody component 20 is preferably made of fibre-reinforced plastic material. At least one rocker panel 30 is interconnected to the underbody component at outer sides thereof, extending in longitudinal direction of the underbody component.

[0049] The rocker panels 30 are in transversal direction (y-direction, transverse to the driving direction x) constructed in a more deformable manner compared to the underbody component 20 such that deformation energy occurring in said lateral direction during impact is absorbed primarily by deformation of the rocker panels 30. The rocker panels 30 are mechanically interconnected to the underbody component 20 by first and second faces 27, 31. They preferably form part of the load bearing structure of the automobile body shell 10 and thereby contribute to the stiffness of the overall structure, i.e. the automobile body shell 10.

[0050] The underbody component 20 normally comprises at least one crossmember 24, 25 which extend in transversal direction (y-direction) foreseen to receive at least part of the load in transversal direction and distribute it within the structure of the underbody component 20. Good results may be achieved if, as shown here. the at least one crossmember 24, 25 is mechanically interconnected to the at least one rocker panel 30 in a mounted position.

[0051] The rocker panels 30 of the shown variation comprise an outer shell 33. Very good results may be achieved if the outer shell is at least partially made of ductile sheet metal and/or composite material. Depending on the field of application the outer shell may comprise several layers of sheet metal and/or composite material. In a preferred variation the outer shell of the at least one rocker panel has in transversal direction an in principle a C-shaped cross-section. The outer shell 33 may comprise at least one drainage, e.g. in the form of one or several holes or openings. If appropriate the drainage can be closed after production. The rocker panels may comprise foam material and/or honeycomb for absorbing impact energy during impact. The foam material and/or honeycomb material is preferably arranged between the underbody component and an outer shell of the at least one rocker panel. The foam material and/or honeycomb material may at least during impact form at least one support between the underbody component and an outer shell of the at least one rocker panel. An underbody component 20 made from fibre reinforced plastic material in combination with rocker panel according to the invention normally comprises one or several first connection faces 27 arranged in sequence or parallel to each other adjacent an outer edge of the underbody component 20. In FIG. 7 this is indicated by a dashed line 36. The first connection faces 27 are foreseen to interconnect the underbody component not only to one or several rocker panels, but also to other parts of the automobile body shell, respectively the passenger cell 10.

[0052] Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the Spirit and scope of the invention.

LIST OF DESIGNATIONS

[0053] 10 Automobile body shell/passenger cell [0054] 20 underbody component [0055] 21 Tunnel [0056] 22 Front end wall structure [0057] 23 Rear end wall structure [0058] 24 First crossmember (inverted transverse channel) [0059] 25 Second crossmember (inverted transverse channel) [0060] 26 Side wall structures [0061] 27 First connection faces [0062] 28 Galvanic isolation and adhesive layer [0063] 29 Mechanical connection means [0064] 30 Rocker panel [0065] 31 Second connection face [0066] 32 Beads [0067] 33 (Outer) Shell [0068] 34 Opening/Drainage [0069] 35 Bottom [0070] 36 Dashed line [0071] 40 Front end side rails [0072] 50 Bulkhead [0073] 60 Faceplate [0074] 70 Rear cross member [0075] 80 Rear seatback member [0076] 90 A pillar inner [0077] CL Center line [0078] L Length [0079] W Width [0080] H Height [0081] x, y, z directions