WO2011128081A1

WO2011128081A1 - Vehicle body and method for producing a vehicle body

Info

Publication number: WO2011128081A1
Application number: PCT/EP2011/001850
Authority: WO
Inventors: Georg KÄSMEIER
Original assignee: Roding Automobile Gmbh
Priority date: 2010-04-12
Filing date: 2011-04-12
Publication date: 2011-10-20
Also published as: DE102010014574B4; DE102010014574A1

Abstract

A vehicle body comprises a self-supporting passenger cell (12) with a trough-shaped floor part (18) made from fibre-reinforced plastic, in particular produced using the RTM process, and side-skirt lower parts (42) which are adhesively bonded to groove-shaped side-skirt sections (40) of the floor part (18) with formation of a closed hollow profile. Moreover, the floor part also comprises a front and a rear wall (20, 24).

Description

Vehicle body and method of manufacturing a

vehicle body

The invention relates to a vehicle body with a self-supporting passenger compartment and to a method for producing such a vehicle body.

In the prior art, there are numerous solutions to produce stable, yet lightweight vehicle bodies. Such solutions use partly light metal and partly plastic, which is carbon fiber or glass fiber reinforced.

From DE 42 43 186 A1, for example, a self-supporting body is known, the passenger compartment is made of plastic. The passenger compartment comprises a single, downwardly open, undercut-free large press, the open bottom of which is closed with several flat covers. This large press is made of glass fiber reinforced polyester resin.

DE 1 275 372 A1 describes a vehicle body with a metal frame, which carries the rest of the body in the form of large plastic parts. The so-called floor pan is formed of two parts, namely a cup-shaped lower part and a shell-shaped upper part, which together form side skirts and floor two-ply.

EP 1 781 527 B1 discloses a vehicle frame with a middle body part, which forms the passenger compartment and consists of metal, and a front carriage and a rear carriage made of a fiber composite material in RTM technology.

The object of the invention is to provide a simple and stable constructed vehicle body and to provide a corresponding manufacturing method thereof.

This object is achieved by a vehicle body with a self-supporting passenger compartment, the passenger compartment being a one-piece, trough-shaped bottom part made of fiber-reinforced, in particular carbon fiber-reinforced plastic, produced in particular in the RTM method. or shell-shaped side sill portions, and further comprising front and rear walls. In addition to the one-piece bottom part, the passenger compartment also produced in particular by RTM process, fiber, especially carbon fiber reinforced, cross-section trough or shell-shaped side skirts lower parts made of plastic, which are glued to the side skirt sections of the bottom part to form a closed at least in cross-section hollow profile.

The rocker sections preferably have upwardly or downwardly open U-sections. The vehicle body according to the invention is composed of extremely few parts, at least as far as the passenger compartment is concerned. The oversized bottom part forms the core of the entire passenger compartment. Its stability is increased by a few adhered thereto parts so that the passenger compartment is self-supporting, namely through the side skirt sections. In addition, a high structural rigidity is achieved, which for example also allows not to keep the passenger compartment stable over the roof, but also to use it as a roadster or convertible body.

Important for the stability are also the front and the rear wall, which are an integral part of the bottom part. These increase the bending stiffness enormously.

In contrast to other methods, as used in the prior art, the RTM process (resin transfer molding) for the production of a self-supporting passenger compartment from very few parts extremely economical and above all suitable for mass production. The RTM process relies on low-cost raw materials (dry fibers, resin containers) and dispenses with the expensive pre-impregnated fabrics. In previous chassis designs with preimpregnated fibers, more tool sets are necessary for the same number of units due to the considerably longer process times, which increases the fixed costs.

As an alternative to the RTM process, the wet-pressing process can also be used. Another advantage of the large-area parts produced in the RTM process is that the parts are manufactured with high precision on both sides as they leave the mold. A post-processing of joining surfaces can be omitted. Compared to the prepreg process, the RTM construction forms some significant advantages. On the one hand, the semi-finished products to be used are more favorable, namely dry fibers and large resin containers. On the other hand, the cold chain can be omitted, and there is no waste due to expired prepregs, which must be stored at -18 ° C and have an expiration date. Prepreg components are also cured under high pressures and high temperatures in expensive autoclaves. In the RTM process, the component does not have to be moved, a heating power is only to be made available for the tool. Also eliminates the complete vacuum structure, which is necessary with prepreg tools. The effort to seal the passenger compartment is reduced compared to conventional frame designs made of metal.

The carbon fiber passenger compartment also makes it possible to carry out the interior without panels, because the surface quality corresponds to that of previously used carbon fiber veneers.

The bottom part is preferably executed undercut, whereby its production can be kept simple.

To further increase the rigidity of the passenger compartment, the side sill panels may include a front and / or a rear pillar portion projecting up from the side sill, the front wall, a rearward side end of the front wall, or a pillar portion (e.g. B. the B-pillar) is glued to form a closed cross-section chamber / are. The side skirts lower parts thus have an L- or U-shape in side view of the body and stabilize the passenger compartment at the corners front and rear or on the B-pillar. Again, it is advantageous that a hollow chamber is formed, which is formed on the one hand by the bottom part and on the other hand by the corresponding portion of the side skirt bottom part. The front column section should project into the area of the upper end of the front wall and / or the rear column section into the area of the side window cutout. That is, the pillar portions extend very far vertically upward to stabilize the vehicle body in the upper portion.

The rear wall can be additionally stabilized by a preferably in the RTM method produced back wall counter wall, wherein the back wall counter wall is bonded to the rear wall of the bottom part to form a closed chamber. The self-supporting passenger compartment according to the preferred embodiment consists only of four parts, namely the bottom part, the two side sill sections and the back wall opposite wall. Thus, the passenger compartment is very inexpensive to produce, especially with little tooling. The bottom part may be formed with a center tunnel section which forms a downwardly open tunnel. However, the front wall also extends above the center tunnel section toward the side sills to stabilize the passenger compartment.

Optionally, as a bottom protection, a metal, in particular an aluminum sandwich plate, be screwed to the underside of the bottom part.

However, the bottom part itself is formed only from a carbon fiber part, namely the bottom part itself, in contrast to the prior art according to DE 1 275 372 A.

The rear wall should also extend very vertically upward, beyond the side sill level to approximately at the level of the lower end of the front window cutout of the finished body.

A significant weight saving for the entire vehicle can be achieved by the fact that seat shells are formed in the bottom part. These seats ensure that no seat itself must be mounted, but only pads are attached to the seat shells. When with the vehicle according to the invention provided body is then made the pedals adjustable, not the seat.

In the bottom part, preferably also in the back wall counter wall, and head restraints can be molded, which also serves the structural strength and the component and weight reduction. The headrests can also be referred to as, generally speaking, rollover structure of the passenger compartment.

Although the bottom part and the side skirts lower parts can also protrude so far that they form at least partially A-pillars. However, this may possibly pose manufacturing problems due to the then required undercut structure. For this reason, it is provided according to an embodiment, a separate, U-shaped circumferential windscreen frame, in particular made in the RTM process to attach to the bottom part, namely by gluing and / or screw. The windscreen frame then forms the A-pillars with its side legs. The vehicle body according to the invention, in addition to the passenger compartment, in particular made of carbon fiber reinforced plastic on a front end and / or rear end, which are attached to the passenger compartment. Front and / or rear carriage are carried out according to the preferred embodiment in the form of a frame structure made of metal, in particular aluminum. This construction with a front and rear frame and a central carbon fiber passenger compartment has many advantages. On the one hand, the crash structure is optimized by the frame structure, and on the other hand, the frame structure can be changed very easily and quickly, in order to make possible different vehicle bodies while the passenger cell remains the same. This creates a kind of modular vehicle architecture that allows for fast variant creation and easy integration of alternative drive variants. In addition, the vehicle body can also be used as a modular delivery part for various vehicle manufacturers, so to speak as a vehicle platform, without the vehicle manufacturers having to give up their identity. Vehicles of different appearance and different wheelbases can be produced via the different front and rear carriages. The advantages of the materials metal, in particular aluminum for front and rear carriage, and carbon fiber are optimal depending on the section used. The deformability of the metal, in particular of aluminum, in the event of a crash is optimized for the front end. In addition, the three segments front, passenger and rear can also be easily replaced after damage. The rear of a frame in turn allows for a rear-wheel drive a good accommodation and accessibility of the engine or.

As previously explained, the passenger compartment is self-supporting, that is, the frame structure of the front car does not pass through the passenger compartment to the rear carriage. The preferred construction for the front and rear carriages is the so-called space-frame construction.

As already explained, in the passenger compartment according to the invention is entirely or almost completely dispensed foam cores, which increase the manufacturing cost and weight. However, at certain points in the shell elements, the benefits of incorporating core materials can be outweighed and taken into account in the design. In the area of the closed hollow profile of the side sill, e.g. the corresponding cavity may be partially filled with a foam core to improve lateral crash stability. Large areas can also be provided with core materials in order to increase the buckling stiffness (sandwich construction).

The shell construction on the one hand lightweight construction is achieved, and on the other cavities for laying cables, air ducts or water pipes are provided.

A preferred embodiment of the invention provides to provide one of the cavities between the shells of the passenger compartment as a sound box of a loudspeaker.

Of course, additional reinforcements, for example, for the belt attachment, etc., can be attached to or embedded in the parts of the passenger compartment. If necessary, such reinforcements are simply inserted into the tool and surrounded by the carbon fiber mat and, so to speak, integrated into the later component. Moreover, the invention relates to a method for producing a body according to the invention. The method provides to produce the bottom part and the side skirt sections as one-piece parts in the RTM process and to glue together. The other parts to be fastened to the passenger compartment should also be designed in one piece as RTM parts, for example the back wall counterpart wall.

The front and the rear wall have according to a preferred embodiment at its upper end a forward or rearward projecting fold, which further increases the stability.

Further features and advantages of the invention will become apparent from the following description and from the following drawings, to which reference is made. In the drawings show:

FIG. 1 shows a perspective view of an embodiment of a vehicle body according to the invention,

FIG. 2 shows a side view of the vehicle body according to FIG. 1,

FIG. 3 shows an exploded view of the passenger compartment of the vehicle body according to the invention,

FIG. 4 shows a side view of a simplified basic diagram of the passenger compartment of the vehicle body according to the invention,

- Figures 5 to 8 are sectional views through four different embodiments of the side sill of Figure 4 along the line A-A, and

- Figure 5 Figure 9 is a perspective view of a simplified basic scheme of the passenger compartment of the vehicle body according to the invention.

1 shows a vehicle body is shown, which consists of three separately preassembled and to be fastened together units, namely a front 10, a self-supporting passenger compartment 12 and a rear frame 14th The front 10 and the rear 14 are designed to accommodate the vehicle axles and designed as a tubular frame, in particular made of aluminum in space frame construction.

The front 10 and the rear 14 are fixed to the passenger compartment 12 each frontally, preferably via plates 16 which are screwed to the passenger compartment 12 in numerous places.

The tubular frame does not extend through the passenger compartment 12, because this is, as already said, self-supporting.

Special features of the vehicle body shown are the simple structure and stable structure of the passenger compartment, which consists solely of large-scale, shell-like, carbon fiber reinforced plastic parts.

In Figure 3, the few items that make up the passenger compartment are shown. The main component is a trough-shaped, one-piece bottom part 18 made of carbon fiber reinforced plastic, which is produced in the RTM process. This bottom part 18 is executed undercut and can be made in a tool with upper and lower parts in one step. The bottom part 18 comprises a plurality of sections, namely a vertically or obliquely vertically upwardly extending front wall 20 with an upper, vertically folded, possibly circumferential edge 22 to increase stability and a rear wall 24 which forms the rear wall of the passenger compartment. Also, the upper edge 26 of the rear wall is folded vertically to provide an increase in stability here as well.

The bottom 28 of the bottom part 18 is also closed except for passages for pedals or cables, in the bottom 28 receptacles 30 are formed for seats.

Also integral part of the bottom part 18 is a downwardly open center tunnel section 32nd

As can be seen in the figures, the center tunnel section 32 merges into the front and rear walls 20 and 24, with the front and rear walls 20 and 24 projecting upwards beyond the center tunnel section 32. Integral part of the rear wall 24 are also molded headrests 34, which serve as rollover protection.

As shown in FIG. 3, the front wall 20 is pulled laterally to the door cutouts 36, so that the front wall 20 also includes side wall sections 38, which classically form the mounting area for the A pillar.

The door cutouts 36 are closed by side skirt sections 40 of the bottom portion down. The side sill sections 40 are upwardly bulging trays or tunnel-like edges of the bottom portion 18 that extend from the floor 28 and are open at the bottom. In cross section, the sill sections 40 are U-shaped.

In order to increase the stability of the passenger compartment in the area of the side skirts, a side skirt bottom part 42 is glued to each Seitenschweiler. This side sill base 42 has a side view according to the illustrated, non-limiting embodiment, a U-shaped configuration.

The side legs of the "U" are formed by upwardly projecting column sections 44, 46.

The side skirts 42 are made in the RTM process and carbon fiber reinforced plastic parts that are executed undercut.

On the one hand, it can be seen in FIGS. 5 to 8 that the illustrated side skirt section 40 is an upwardly bulging tunnel-like section with its free end 50 running down, and on the other hand that the side skirt lower part 42 likewise has a shell-like shape, in the example shown in FIG Essentially designed in cross-section L-shaped.

One leg of the "L" lies on the inside by overlapping on the edge 50 of the side sill section 40 and is adhesively bonded to the entire area in this area.The other end of the "L" lies flat on the underside of the bottom 28 and is also in this area continuous and glued over the entire surface. Through this two-shell structure results in a cross section closed hollow profile 52 for the thus formed, very stable side skirts.

In the embodiment according to FIG. 6, flat core materials 53, which serve to increase the rigidity, are embedded in the walls of the side sill section 40 and / or the lower part 42. These plates 53 are placed in the manufacture of the side skirt portion 40 and the lower part 42 between two fiber mats and thereby embedded in the parts.

For additional stabilization, the side skirt lower part 42 can be pulled around a core 54, for example made of foam, in sections (see FIG. 7), so that in this region the side skirt lower part 42 has a fully filled section. But also in this section, the side skirt portion 40 complements the side skirt bottom 42 to a closed circumferential profile, which is not completely hollow. Alternatively or additionally, according to FIG. 8, a section of the side skirt lower part 42 may carry a locally attached reinforcing body as the core 56, which however is not completely surrounded by the lower part 42 but is only laterally attached to the side skirt lower part 42 and connected to it. This core 56 partially fills the cavity 52 of the closed hollow profile partially or completely.

The view according to FIG. 4 is not the complete side view of the passenger compartment, but rather a stylized side view reduced to the side sill area, illustrating only the various possibilities of reinforcing the side sill by partially inserted cores 54, 56. The rigidity of the passenger compartment is also increased by the fact that the front column section 44 serves as a shell, which closes the likewise shell-like side wall 38, so that in this area a substantially closed chamber is formed.

The same applies to the rear pillar portion 46, which together with the edge 26 bent backwards, the rear wall 24 and a back wall counter wall 60 likewise form a chamber which is preferably closed in the cross-sectional profile. The counter wall 60 is a carbon fiber reinforced plastic part, which is manufactured in one piece in the RTM process and is preferably designed undercut.

The counter wall 60 is closed with the rear wall 24 and the Seitenschweller- divide 42 circumferentially and glued surface, here also be folded edges 62 provide additional reinforcement and an overlap area in which the adhesive application 55 can be made.

Not shown is an optionally provided underbody protection plate, in the form of an aluminum sandwich plate, which is to protect the bottom 28 and optionally also close the central tunnel 32.

The front pillar portion 44 protrudes to the upper end of the front wall 20 and the side wall 38, which extend up to the side window opening in a vertical upward direction.

The rear pillar portion 36 also extends into the region of the side window cutout, ie in the region of the upper end of the seat back.

A produced in RTM process, U-shaped circumferential windscreen frame 70 (see Figure 1) is bolted or glued to the bottom part 12. This frame 70 then forms the A-pillar.

The passenger compartment 12 consists essentially of only four bowl-shaped parts, namely the bottom part 18, the Rare bottom parts 42 and the counter wall 60. These parts are responsible for the self-supporting stability of the passenger compartment.

Of course, the vehicle body shown may also be designed for a four-seater, possibly with a side skirt lower part 42 extending from the A to the B or even the C-pillar and a continuous floor part 8 which extends to the rear wall 24 of the passenger compartment , Alternatively, however, a front and a rear floor part could be executed, which are glued together in the region of the backrests of the front seats. The undercut-free shell construction allows easy production of the few items and the formation of closed chambers or hollow sections.

The chambers can also be used to accommodate installation parts or to run pipes or cables. The chamber resulting between the side wall 38 and the front pillar portion 44 is designed, for example, as a sound box of a hi-fi system.

The advantage of the RTM process, in which the shell-shaped body can be produced on both sides with high surface quality and high accuracy, for example, from Figure 5. Here it can be seen that the side sill base 42 on the one hand on its outside with the edge 50 and on the other hand is glued on its inside with the bottom 28, so has two opposite sides that represent unprocessed connection surfaces to other parts. FIG. 9 serves only to illustrate in principle the basic scheme of the present passenger cell constructions, with the trough-shaped bottom part 18 and the closed hollow profiles which result in the area of the side branches 40.

It should also be emphasized that the center tunnel 38 may be omitted and that the bodies housed in the side sills may be implemented as energy-absorbing foam blocks.

The bottom part 18 is manufactured in a closed tool in one operation and is preferably designed purely monolithic, as it also applies to the side skirt bottom parts 42 and the counter wall 62. Optionally, threaded sleeves or bolts, bolts, etc. may be embedded in these parts, ie quite generally parts for attachment of adjacent parts.

The production of large-scale body parts in the RTM process is carried out in a customized tool with upper and lower part, first in the lower part an un-saturated, dry carbon fiber mat is inserted and then the tool is closed before the liquid plastic in the cavity is introduced. The molding compound is injected in particular via a heated prechamber and distribution channels in the so-called mold cavity, where the mass penetrates into the carbon fiber mats and finally cures under heat and pressure. The parts produced need only be trimmed at the edge, otherwise no further processing is necessary.

Instead of carbon fiber mats alternative fiber mats could also be used.

Furthermore, the wet pressing method, in which impregnated fiber mats are pressed between two molds in the form, can be used for the production of the bottom part and / or the side skirt bottom part.

Claims

claims

1. vehicle body, with

a self-supporting passenger compartment (12) which is a one-piece, in particular in the RTM process produced, trough-shaped bottom part (18) made of fiber-reinforced, in particular carbon fiber reinforced plastic, which channel-shaped side skirt sections (40), a front and a rear wall (20, 24) has, as well

with, in particular in the RTM process produced, in cross-section groove-shaped side skirts lower parts (42), which are integrally made of fiber-reinforced, in particular carbon fiber reinforced plastic and with the side skirt sections (40) to form a closed at least in cross-section hollow profile (52) are bonded.

2. Vehicle body according to claim 1, characterized in that the side sill lower parts (42) have a side skirt from the upstanding front and / or rear pillar portion (44, 46) on the front wall (20) or a bottom part-side rear pillar portion, preferably the Rear wall (24), is glued to form a closed cross-section chamber.

3. Vehicle body according to claim 2, characterized in that the front pillar portion (44) into the region of the upper end of the

Front wall (20) and / or the rear pillar portion (46) projects into the region of the side window cutout.

4. Vehicle body according to one of the preceding claims, characterized in that the front wall (20) has a side wall portion (38) which extends to the side sill.

5. Vehicle body according to one of the preceding claims, characterized in that in the bottom part (18) a center tunnel section (32) is formed, wherein the front wall (20) extends above the center tunnel section (32) to the Seitenschweilern.

6. Vehicle body according to one of the preceding claims, characterized in that the front wall (20) and / or the rear wall (24) has a substantially vertically folded edge (22, 34).

7. Vehicle body according to one of the preceding claims, characterized in that one produced in particular in the RTM process

Rear wall opposite wall (60) made of fiber-reinforced, in particular carbon fiber reinforced plastic with the rear wall (24) of the bottom part (18) is glued to form a closed chamber.

8. Vehicle body according to one of the preceding claims, characterized in that a front end (10) and / or a rear carriage

(14) in the form of a frame structure made of metal, in particular of aluminum, are attached to the passenger compartment (12).

9. Vehicle body according to one of the preceding claims, characterized in that the closed hollow profile (52) of the side sill is only partially filled with a foam core.

10. Vehicle body according to one of the preceding claims, characterized in that the bottom part (18) and / or the side skirt bottom parts are formed without an undercut.

11. Vehicle body according to one of the preceding claims, characterized in that the side sill lower parts (42) in side view of the body have an L or U-shape.

12. Vehicle body according to one of the preceding claims, characterized in that the side sill lower parts (42) have a cup-shaped shape and in particular have seen an L-shaped or U-shaped cross-section in the vehicle longitudinal direction.

13. Vehicle body according to one of the preceding claims, characterized in that the side sill lower parts (42) are integrally made of fiber-reinforced plastic and bonded to the side sill sections to form a closed at least in cross-section hollow profile.

14. A method for producing a vehicle body according to one of the preceding claims, characterized in that the bottom part (18) and the side skirt sections (40) are produced as one-piece parts in the RTM process, in particular carbon fiber reinforced, and are glued together to form Hollow profiles or hollow chambers.