DE102004062932A1 - Rear floor structure, for motor vehicle, has structure body, extended over entire vehicle width, which has structures realized as cast component in upper or lower load path planes as well as longitudinal and transverse load paths - Google Patents

Abstract

Rear floor structure has a structure body (1), which extends over the entire vehicle width. The structure body has a number of structures realized as cast component in upper and lower load path planes (2,3) as well as longitudinal and transverse load paths.

Description

The Invention relates to a rear floor structure of a motor vehicle, in particular a passenger car.

floor structures On motor vehicles become conventional in a so-called steel shell construction formed, wherein a plurality of open or closed Hollow profiles in the form of longitudinal and crossbeams welded together and / or connected by means of known mechanical fastening means become. Due to the high number of components including the required fasteners Significant manufacturing costs are recorded, which in addition to with associated with a high weight of the soil structure.

To counteract this high weight as well as the high production costs are, inter alia, with the EP 0 900 716 A1 so-called cast nodes made of light metal, such as aluminum or magnesium, or proposed plastic, which in turn are connected by means of light metal extrusions and / or plastic profiles via molded connecting parts to a support structure. By this measure is certainly already a certain success in terms of reducing the number of components and the manufacturing costs recorded.

task The present invention is to provide a rear floor structure of a Motor vehicle to create, in terms of conventional rear floor structures even lighter weight and their production costs even further minimized.

According to the invention Task solved accordingly by a rear soil structure, the in turn by a largely over the entire vehicle width formed extending structural body is, in turn, as a cast component a plurality in an upper and / or a lower load path level arranged as well as longitudinal and Has transverse load paths realizing structures.

By This measure In particular, the production cost is minimized because the required Effort to conventional Connecting a plurality of individual components with each other to a supporting Structure largely eliminated. Further, due to the fact that additional fasteners are dispensable to record a significant weight saving.

The under claims describe preferred developments or refinements of Invention.

Thereafter, according to a first preferred embodiment of the invention, the structural body may be integrally formed. According to a further preferred embodiment, it may also be appropriate to form the structural body by two separately fabricated, but in the area divided Querlastpfade firmly connectable substructures, whereby the production of the casting itself is facilitated. In view of this, furthermore, the divided transverse load paths can each be connected to one another directly or via an interposed separately manufactured profile element. By said profile element tolerances can be compensated easily and inexpensively while maintaining the inherently advantageous manufacturing integral cast structures. Furthermore, there is a slight adaptation of the structural body to vehicle types with different vehicle widths. According to a particularly advantageous embodiment of the invention, a main longitudinal load path is arranged on both sides of the motor vehicle in the upper load path plane, which in turn connects a die of a crash box with a sill. In an inventive development is further proposed that a rearwardly facing end portion of the main longitudinal load path is replaced by at least one separately manufactured and connectable with the same profile element or by means of such a variable in length, which also extremely easy to adapt the rear floor structure to different Vehicle types is guaranteed. The said separately manufactured profile elements can be formed by inexpensive producible castings, extruded profiles, hydroforming profiles or roll-profiled profiles. It is further considered appropriate if the matrix of the crash box is integrated into the structure of the main longitudinal load path or of the at least one profile element. Furthermore, it is proposed that a rear transverse load path, starting from a main longitudinal load path in the vehicle transverse direction, is guided from the upper load path plane into the lower load path plane, back into the upper load path plane and finally on to the opposite main longitudinal load path. As the invention further provides, a front transverse load path is arranged in the lower load path plane and formed by a bottom profile for connecting a bottom middle part and connected on both sides by means of an auxiliary longitudinal load path with the main longitudinal load paths. As the invention still provides, the rear and front transverse load paths are connected to one another by means of two lower longitudinal load paths spaced from one another in the vehicle transverse direction and arranged in the lower load path plane, as a result of which a high stability of the overall composite is recorded. It is also conceivable that the formed as a bottom profile front Querlastpfad itself continues down over the height of the soil profile down and merges into an integrally molded battery carrier. In that regard, the battery tray may have a paragraph for fixing the battery in the vehicle longitudinal direction. In contrast, the battery holder separate holder for fixing the battery in the vehicle transverse direction and can be assigned to the top. Furthermore, it is proposed in the sense of the invention that the structural body integrally on or molded connections for various attachments of the chassis, as for springs, transverse and / or trailing arm, tie rods, spring link and / or other attachments. According to a further advantageous measure, it is provided that defined stiffening and / or deformation zones of the longitudinal and / or transverse load paths can be achieved by means of defined local ribs or the like. The ribs o. The like. Are arranged such that a graded stiffness of the rear floor structure respectively of the structural body in the vehicle longitudinal and / or transverse direction can be achieved. As the invention also provides, may be provided between the main longitudinal load paths a separately manufactured and trough-shaped underbody, which in turn is supported on integral fastening means of one or more of the lower transverse and / or longitudinal load paths. The trough-shaped underbody can be formed for example by a plastic-metal hybrid component. In this respect, it is also provided that in order to ensure a flat support surface for a known topsoil, the upper edge of said trough-shaped subfloor continues at least partially upwards beyond the main longitudinal load paths addition. The topsoil can span the entire cargo space width of the motor vehicle and is preferably designed as an extruded profile. Conveniently, the topso also has one or more preferably closable openings to ensure accessibility to the subfloor. As the invention finally provides, the structural body consists of cast metal, preferably of light metal casting.

The The invention will be described below with reference to the drawings illustrated embodiments explained in more detail. It demonstrate:

1 a small-scale representation of the rear floor structure according to the invention (perspective view),

2 the soil structure after 1 in a large-scale representation,

3 the soil structure after 2 in a plan view,

4 the view "A" after 3 .

5 a detailed perspective view of the soil structure seen from the front left top,

6 the perspective detailed representation of the soil structure seen from the top right top,

7 the perspective detailed representation of the soil structure seen from the bottom right rear,

8th seen the perspective detail of the soil structure from bottom to right rear,

9 a diagram of the deformation force "F" on the deformation path "s" with respect to an inventively designed rear floor structure in the event of a rear crash, and

10 - 13 Further advantageous embodiments of the rear floor structure.

The 1 and 2 show very schematically a rear floor structure of a motor vehicle, in particular a passenger car, according to the invention by a integral as a cast component, thus integrally formed and extending as far as possible over the entire vehicle width structural body 1 is formed and a plurality in a so-called upper and / or a so-called lower Lastpfadebene 2 . 3 arranged as well as longitudinal and transverse load paths 4 . 5 ; 6 . 7 ; 8th . 9 ; 10 . 11 having realizing structures.

According to a preferred embodiment, the structural body 1 made of cast metal, preferably of light metal casting, for example of aluminum or magnesium or suitable alloys thereof, and can be prepared by the known and particularly economical die-casting or sand casting. However, it is also conceivable and is covered by the invention, said structural body 1 to manufacture from a suitable and possibly reinforced plastic.

In the automotive industry is traditionally a division of the vehicle structure in transverse and side members instead. This nomenclature makes sense when it comes to the description of the carrier used in shell or frame construction as individual components. Since these conventional carrier completely by the formed as an integral cast component and equipped with extremely complex geometries structural body 1 In the present case, the term "load paths" is used to ensure a clear distinction from the multi-part designs.

After that, how is particularly good 2 in common view with 3 seen in the upper load path level 2 on both sides of the motor vehicle each have a main longitudinal load path 4 . 5 arranged, in turn, a die 12 a so-called crash box 13 connects with a known, but not shown here sill.

Said crash box 13 is presently formed by a tapered in diameter hollow profile, for example, an aluminum round profile and into a bore of the die 12 inserted. The energy absorption in the event of a rear crash occurs due to the friction of the crash box 13 within said bore and by deformation thereof ( 8th ).

As for the connection of the main longitudinal load paths 4 . 5 As far as the sills are concerned, the main longitudinal load paths 4 . 5 frontally so-called attachment surfaces 14 auf, which in turn are positively pushed onto the corresponding sill and connected to this preferably cohesively, for example glued (esp. 2 to 5 ).

The main longitudinal load paths 4 . 5 are further by means of a rear and a front transverse load path 6 . 7 connected in the vehicle transverse direction, wherein the rear transverse load path 6 , starting from the one main longitudinal load path 4 in the vehicle transverse direction seen from the upper Lastpfadebene 2 in the lower load path level 3 and finally back to the upper load path level 2 to the opposite main longitudinal load path 5 is guided ( 2 ).

The front transverse load path 7 is in turn in the lower load path level 3 arranged and formed by a bottom profile for connecting a bottom middle part, not shown in detail, and on both sides by means of an auxiliary longitudinal load path 8th . 9 with the main longitudinal load paths 4 . 5 connected (esp. 2 . 3 and 5 ).

Said not shown in detail bottom middle part is preferably formed with the present as an angle profile front transverse load path 7 (Soil profile) connected by gluing, however, any other known fastening measures, such as welding and / or by means of conventional mechanical fastening means are also conceivable.

By this measure, the structural body 1 Even without conventionally to be carried out separately Schubfeldversteifungen extremely torsionally stiff. Furthermore, by the above special connection of the structural body 1 Crash loads from a rear crash defined in the sill and floor profile respectively floor middle section can be divided at the sills and the bottom center part.

Between rear and front cross load path 6 . 7 in the present case run in the lower load path level 3 two spaced apart in the vehicle transverse direction lower longitudinal load paths 10 . 11 and connect the two shear paths 6 . 7 together, so that now an extremely stable frame is formed, which, as already demonstrated above, contributes to a particularly high stability of the overall composite.

Like that 1 to 7 , in particular the 6 can be seen further, is formed as a soil profile front transverse load path 7 continues beyond the height of the vertical web of the angle profile downwards and goes into an integrally molded, present frame-shaped battery carrier 15 above. According to a preferred embodiment is also a paragraph 16 on the battery carrier 15 provided for fixing the battery not shown in detail in the vehicle longitudinal direction.

To fix the battery in the vehicle transverse direction and upwards are the battery carrier 15 expediently assigned to a separate holder known (not shown in detail).

The floor structure according to the invention in the form of the structural body formed as an integral cast component 1 has a high integration potential and is therefore particularly predestined to accommodate the Hinterachsfahrwerk particularly simple and inexpensive, whereby a conventional additional subframe is avoided. In this respect, integrally molded or molded connections 17a -E for various attachments of the chassis, such as springs, transverse and / or trailing arm, tie rods, spring link u. Like. Be provided more.

After that gem. 7 in the upper load path level 2 at the main longitudinal load path 4 . 5 connections 17a for control arms, connections 17b for trailing arms and connections 17c intended for the suspension.

In the lower load path level 3 , present at the lower longitudinal load paths 10 . 11 , are also connections 17d intended for wishbone. Furthermore, at the rear transverse load path 6 connection 17e provided for spring link.

Said connections 17a -E can be formed by recesses, such as holes, by indentations of separate components, such as threaded sleeves, inter alia more, or by special formations of the casting material, such as spring plate including hole for fixing the suspension. Another indentation in the Main longitudinal load path 4 . 5 By the way, also for the matrix 12 the crash box 13 be provided.

As well can no further details shown connections in the form of recesses for cable clips, cast Threaded bushes for for example, a towing eye and much more consideration Find.

For the expert certainly easy to understand, are the ways, more, here not closer Specified components, functions and component connections to represent the cast component according to the invention, almost unlimited. In particular, can be particularly simple and economical complex geometries for connection to neighboring modules of the Vehicle body, such as the vehicle body (hat) or the top already mentioned Floor center section, consisting of sills and floor profiles produce.

Furthermore, by means of defined local ribs 18 o. The like. Also defined stiffening and deformation zones of the longitudinal and / or transverse load paths 4 . 5 ; 6 . 7 ; 8th . 9 ; 10 . 11 achievable. That's how it is 2 especially good ribbing 18 in the area of the transverse load path branching of the rear cross load path 6 seen.

The ribs 18 can be arranged in an advantageous manner such that a graded stiffness of the rear floor structure respectively of the structural body 1 in vehicle longitudinal and / or transverse direction can be achieved.

9 shows an example of a diagram of the deformation force "F" on the deformation path "s" in the event of a rear crash. Thereafter, in the context of extensive experiments, the entire rear area, consisting of the inventively designed soil structure in the form of a structural body 1 made of cast, the subsequent crash box 13 including a cross member 19 and a reversible absorber consisting of, for example, plastic and / or an elastomer 20 be formed graduated in its stiffness such that depending on a certain introduced force (deformation force "F") due to a rear crash deformation largely limited to this rear area and the passenger compartment area 21 remains protected against deformation and thus an effective survival space in said passenger compartment 21 is created.

In contrast to the conventional design of the crash box 13 behind, was now to protect the structural body 1 given the opportunity to assume higher design speeds and based on existing crash tests a one-sided load and much higher vehicle masses. Furthermore, the use of the "tapering principle" for said crash box allows 13 a high absorption potential with simultaneous integration of the matrix 12 in the main longitudinal load path 4 . 5 , The reversible absorber 20 in the form of a bumper, not shown, assumes an absorption potential of about 6 km / h, for example, in "parking bumps". To be able to absorb small forces, was further in the following area between the crash box 13 and the rear cross load path 6 on a ribbing 18 the main longitudinal load paths 4 . 5 waived. That is, they can give absorbing energy within certain limits by the geometry chosen. In the area of the self-protection zone, on the other hand, the stiffness of the longitudinal and transverse load paths became 4 . 5 ; 6 . 7 ; 8th . 9 ; 10 . 11 through the use of ribbing 18 so locally defined increases, that although the connection areas of the trolleys can be deformed, but sets a maximum rigidity in the area where both the structural body 1 as well as the bottom middle part contribute to the increased rigidity, accordingly in the area of the front cross load path 7 and the connection of the structural body 1 to the sills.

In summary, it should therefore be noted that the special design of the structural body 1 a much higher energy can be absorbed together with the adjacent attachments than with a shell construction in steel. Through the ribbing 18 is a sufficient rigidity for suspension connection and the introduction of force in the central region of the structural body 1 allows.

To an even higher stiffening of the structural body 1 To achieve this, it may be appropriate to switch between the main longitudinal load paths 4 . 5 to provide a separately produced trough-shaped subfloor, which in turn on integral fastening means of one or more of the lower longitudinal and / or transverse load paths 6 . 7 ; 8th . 9 ; 10 . 11 supported. As it were, a false bottom is created with its own increased rigidity (not shown in detail).

When trough-shaped Trained subsoil has become a plastic-metal hybrid component especially proven, however, any other suitable material is also conceivable.

To ensure a flat bearing surface for a not shown in detail, but known per se topsoil, the upper edge of the said trough-shaped subfloor may at least partially upwards on the main longitudinal load paths 4 . 5 continue.

The topsoil is preferably as a strand formed press profile and spans the entire load compartment width of the motor vehicle. Likewise, one or more, preferably closable openings in the topsoil to ensure accessibility to the subfloor are considered advantageous, so that the cavity formed, for example, also for stowing various utensils, such as tools u. Like. Or for the integration of other components, such as electronic components, can be used.

The above embodiment essentially relies on a one-piece structural body 1 from. However, a structural body is also covered by the invention 1 , which, for its part, can be neglected by guaranteeing or increasing the process reliability and without neglecting the component and functional integrity, by means of two separately produced, but in the area divided, transverse load paths 6 . 7 firmly interconnected substructures 1a . 1b is formed, whereby, in particular in the case of a crash and a required repair, for example, only one of the two substructures 1a . 1b due to damage needs to be replaced ( 10 ).

Furthermore, this measure can also have an advantageous effect, if one strives to uniform components (partial structures 1a . 1b ) for different types of vehicles. In that regard, it is conceivable, the shared transverse load paths 6 . 7 not directly connect to each other, but between them at least one separately manufactured profile element 6a . 6b to set, which are extremely comfortable for a width differences of different types of vehicles into account and on the other can be compensated for unavoidable tolerances. Likewise, it is conceivable the profile element 6a . 6b to the finer gradation of the stiffness of the structural body depending on the vehicle type 1 to be used in vehicle transverse direction.

As far as shows 11 an embodiment whose front transverse load path 7 " is formed only "split, whereas a central portion of the rear divided Querlastpfades 6 on top of that by a separately manufactured profile element 6a is replaced. In contrast, in 12 an embodiment shown in which the middle portion of both the rear and the front transverse load path 6 . 7 by a separately manufactured profile element 6a . 7a is replaced. The profile element 6a . 7a are preferably formed by simple and inexpensive to manufacture castings, extruded profiles, hydroforming profiles or roll-profiled profiles of, for example, light metal.

Gem. The 10 to 12 features the structural body 1 Not only potential for easy and cost-effective compensation of tolerances in the vehicle transverse direction and of differences in width with respect to different types of vehicles, but also measures are proposed that are suitable for compensating for differences in length. Essentially, these are manufactured separately and with the main longitudinal load path 4 . 5 connectable profile elements 4a . 5a provided, in turn, as in the 10 to 12 shown, a rearwardly facing end portion of the main longitudinal load path 4 . 5 replace or open the possibility to change its length.

So gem. the 10 to 12 the structural body 1 with its substructures 1a . 1b on the relatively complex structure to the rear cross load path 6 limited, whereas the relatively "simple" rear end portions of the main longitudinal load paths 4 . 5 through said profile elements 4a . 5a are replaced, which in turn can be preferably also formed by simple and inexpensive to be produced castings, extruded profiles, hydroforming profiles or roll-profiled profiles.

It goes without saying for the person skilled in the art that the profile elements 4a . 5a then the matrix 12 the crash box 13 record or such a template 12 is integrated in the same.

13 finally shows the one-piece structural body described in more detail above 1 with main longitudinal load paths 4 . 5 whose rear end sections also by profile elements 4a . 5a replaced or changeable in length.

1

body structure

2

upper Last path level

3

lower Last path level

4

Main longitudinal load path

4a

profile element

5

Main longitudinal load path

5a

profile element

6

rear Lateral load path

6a

profile element

7

front Lateral load path

7a

profile element

8th

Auxiliary longitudinal load path

9

Auxiliary longitudinal load path

10

lower Longitudinal load path

11

lower Longitudinal load path

12

die

13

Crash box

14

connection surfaces

15

battery carrier

16

paragraph

17a-e

connections

18

ribbings

19

crossbeam

20

absorber

21

Passenger cell area

Claims (23)

Rear floor structure of a motor vehicle, characterized by a structural body extending as far as possible over the entire width of the vehicle ( 1 ), which in turn, as a cast component, has a plurality in an upper and / or a lower load path plane (FIG. 2 . 3 ) and longitudinal and transverse load paths ( 4 . 5 ; 6 . 7 ; 8th . 9 ; 10 . 11 ) realizing structures. Rear floor structure according to claim 1, characterized in that the structural body ( 1 ) is formed in one piece. Rear floor structure according to claim 1, characterized in that the structural body ( 1 ) by two separately produced, but in the area divided transverse load paths ( 6 . 7 ) substructures which can be firmly connected to each other ( 1a . 1b ) is formed. Rear soil structure according to claim 3, characterized in that the divided transverse load paths ( 6 . 7 ) each directly or via an interposed separately manufactured profile element ( 6a . 7a ) are connectable to each other. Rear floor structure according to one of claims 1 to 4, characterized in that in the upper load path plane ( 2 ) on both sides of the motor vehicle each have a main longitudinal load path ( 4 . 5 ), which in turn has a die ( 12 ) a crash box ( 13 ) connects to a sill. Rear floor structure according to claim 5, characterized in that a rearwardly facing end portion of the main longitudinal load path ( 4 . 5 ) by at least one separately manufactured and connectable with the same profile element ( 4a . 5a ) is replaced or by means of such in its length changeable. Rear floor structure according to one of claims 4 to 6, characterized in that the separately manufactured profile elements ( 4a . 5a . 6a . 7a ) are formed by castings, extruded profiles, hydroforming profiles or roll-profiled profiles. Rear floor structure according to one of claims 5 to 7, characterized in that in the structure of the main longitudinal load path ( 4 . 5 ) respectively of the at least one profile element ( 4a . 5a ) die ( 12 ) of the crash box ( 13 ) is integrated. Rear floor structure according to one of claims 1 to 8, characterized in that a rear transverse load path ( 6 ), starting from a main longitudinal load path ( 4 ) seen in the vehicle transverse direction from the upper load path level ( 2 ) in the lower load path level ( 3 ), back to the upper load path level ( 2 ) and finally on to the opposite main longitudinal load path ( 5 ) is guided. Rear floor structure according to one of claims 1 to 9, characterized in that a front transverse load path ( 7 ) in the lower load path plane ( 3 ) and formed by a bottom profile for connecting a bottom middle part and on both sides by means of an auxiliary longitudinal load path ( 8th . 9 ) with the main longitudinal load paths ( 4 . 5 ) connected is. Rear floor structure according to one of claims 1 to 10, characterized in that the rear and front transverse load paths ( 6 . 7 ) in the lower load path plane ( 3 ) by means of two mutually spaced in the vehicle transverse direction lower longitudinal load paths ( 10 . 11 ) are interconnected. Rear floor structure according to one of Claims 1 to 11, characterized in that a front transverse load path ( 7 ) continues downwards beyond the height of the soil profile and into an integrally formed battery carrier ( 15 ) passes over. Rear soil structure according to claim 12, characterized in that the battery carrier ( 15 ) a paragraph ( 16 ) for fixing the battery in the vehicle longitudinal direction. Rear floor structure according to one of claims 12 and 13, characterized in that the battery carrier ( 15 ) Separate holder for fixing the battery in the vehicle transverse direction and can be assigned to the top. Rear floor structure according to one of claims 1 to 14, characterized in that the structural body ( 1 ) integrally molded or molded connections ( 17a -E) for various attachments of the chassis, as for springs, transverse and / or trailing arm, tie rods, spring link and / or other attachments has. Rear soil structure according to one of claims 1 to 15, characterized in that by means of defined local ribs ( 18 ) o. The like. Stiffening and / or deformation zones of the longitudinal and / or transverse load paths ( 4 . 5 ; 6 . 7 ; 8th . 9 ; 10 . 11 ) are achievable. Rear soil structure according to claim 16, characterized in that the ribs ( 18 ) o. The like. Are arranged such that a stepped stiffness of the rear floor structure respectively of the structural body ( 1 ) is achievable in vehicle longitudinal and / or transverse direction. Rear floor structure according to one of claims 1 to 17, characterized in that between the main longitudinal load paths ( 4 . 5 ) a separately produced and trough-shaped subfloor is provided, which in turn on integral fastening means of one or more of the lower transverse and / or longitudinal load paths ( 6 . 7 ; 8th . 9 ; 10 . 11 ) is supported. Rear soil structure according to claim 18, characterized characterized in that the trough-shaped trained underbody is a plastic-metal hybrid component. Rear floor structure according to one of claims 18 and 19, characterized in that to ensure a flat support surface for an upper floor, the upper edge of said trough-shaped subfloor at least partially upwards over the main longitudinal load paths ( 4 . 5 ) continues. Rear soil structure according to claim 20, characterized characterized in that the topsoil the entire load compartment width of Motor vehicle spans and is preferably designed as an extruded profile. A rear floor structure according to any one of claims 20 and 21, characterized in that the topsoil one or more preferably closable openings to guarantee accessibility to the subsoil has. Rear floor structure according to one of claims 1 to 22, characterized in that the structural body ( 1 ) made of cast metal, preferably light metal casting.