DE102004062933A1 - Floor assembly for motor vehicle body, has base unit part formed of base profiles, and rear end designed as integral casting component, where base part and rear end are connected with each other in form-fit and firmly bonded manner - Google Patents

Abstract

The assembly has a base unit part (1) consisting of base profiles (3) arranged next to each other and pointing in a vehicle longitudinal direction. A rear end (2) is designed as integral casting component or completed from individual casting components, where the part and the end are manufactured from light metal e.g. aluminum or magnesium. The part and the end are connected with each other in a form-fit and firmly bonded manner.

Description

The The invention relates to a floor assembly of a motor vehicle body, with a floor middle section and a rear section.

The Floor group of the vehicle structure can be known in the Basic modules Structural beams Divide the front, bottom center section and structural support at the rear. These Modules are relatively large Assemblies are and 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 by means of known mechanical fastening means connected to said modules. Due to the high number of components including the required fasteners are significant Manufacturing costs recorded on top of that with a high weight of associated with individual modules.

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.

regardless of which it is necessary in the context of the final assembly of a motor vehicle, individual support structures or modules, for example, to a Floor group to connect with each other. It should be noted that the joints or joints between the individual modules decisive for the stiffness characteristics of the entire vehicle. The connection / joints must be designed load-appropriate be to the transfer to ensure any crash loads in the neighboring module. Furthermore, the connection / joints between the modules should be have sufficient potential for tolerance compensation.

task The invention therefore relates to a floor assembly of a motor vehicle body, to create with a bottom center section and a rear section, the for a simple and inexpensive to produce and on the other hand the high rigidity and strength requirements especially with regard to a rear and / or side crash fair becomes. Furthermore, should a sufficient potential for tolerance compensation be given.

According to the invention the object is achieved in conjunction with the features in the preamble of claim 1, characterized in that the bottom middle part of a plurality of juxtaposed and largely pointing in the vehicle longitudinal direction bottom profiles is formed, which in turn are bounded on the body side by a respective sill profile and the rear end formed as an integral cast component or is completed from a plurality of individual cast components, wherein the bottom middle part and the rear carriage are both positively and materially firmly connected to each other. In a further embodiment of the invention, the bottom profiles and sill profiles of the bottom middle part are formed as closed in cross section hollow sections, preferably continuous casting profiles. If a rear carriage designed as an integral cast component is provided, this is formed by a structural body extending as far as possible over the entire width of the vehicle, which has structures having at least two main longitudinal load paths and a front and a rear transverse load path. In contrast, the individual to a rear end completed cast components comprise at least two main longitudinal members and a front and a rear cross member, front and rear cross member, the main longitudinal members connect in the vehicle transverse direction with each other. In a particularly advantageous embodiment, the main longitudinal load paths / main longitudinal members of the rear carriage for positive connection of the same to the bottom center part frontally one or more surface receiving structures, which in turn are at least at the corresponding sill profile of the bottom middle part can be fixed. In that regard, it is also provided that the connecting portions between the main longitudinal load path / main longitudinal member and at least the sill profile of the bottom middle part, which are loaded in terms of a rear crash and / or a side impact due to the respective force to pressure, are bonded together by gluing and connecting portions between the main longitudinal load path / Main longitudinal members and at least the sill profile of the bottom middle part, which are loaded in terms of a rear crash and / or a side impact due to the respective force to train, are connected by welding. As the invention further provides, the front transverse load path realizing structure or the front cross member on a surface portion with ridges and depressions, wherein the bottom middle part, supported on said surface portion, in the region of the formed increases by welding and / or in the region of the recesses Bonding with the transverse load path / cross member is firmly connected. Finally, it is provided that the bottom middle part and the rear of light metal, preferably made of aluminum or Ma magnesium.

The Invention will now be described schematically with reference to the drawings illustrated embodiment explained in more detail. It demonstrate:

1 the underbody according to the invention, with a bottom middle part and a rear carriage in a perspective view,

2 the rear carriage seen in a perspective solo view from front left top,

3 the view "A" after 1 , and

4 the perspective detail view of the connection area between the bottom middle part and the front Querlastphad / cross member of the rear carriage.

The 1 shows very schematically the rear portion of the floor assembly of a motor vehicle body, consisting of a bottom middle part 1 and a rear car 2 ,

After that is the bottom middle part 1 by a plurality of juxtaposed and largely pointing in the vehicle longitudinal direction bottom profiles 3 formed, in turn, the body exterior side by a respective sill profile 4 are limited.

According to a preferred embodiment, both the soil profiles 3 as well as the sill profiles 4 designed as closed in cross section hollow sections and preferably firmly connected to each other by gluing. Of course, other joining methods, such as welding, and / or mechanical fastening means are conceivable.

By This measure is especially in the vehicle longitudinal direction a very rigid composite created, which is particularly advantageous affects the overall stiffness of the vehicle body.

said Hollow profiles are also extremely easy and inexpensive Produce continuous casting profiles, with a view to a desired Lightweight, lightweight metals, such as aluminum or magnesium or suitable alloys using these materials, especially to offer.

What the rear 2 As far as this is concerned, it may be designed as an integral cast component which, as it were, has a structural body extending over the entire width of the vehicle with at least two so-called main longitudinal load paths 5 . 6 and two, the main longitudinal load paths in the vehicle transverse direction interconnecting Querlastpfade 7 . 8th , present a front and a rear transverse load path 7 . 8th realizing structures includes.

Also here is enforcing the desired lightweight construction method of light metal casting favored, with known casting methods, such as Die casting process, can be used.

in the Although motor vehicle construction traditionally finds a classification of Vehicle structure in longitudinal and transverse beams instead. However, this nomenclature only makes sense if it is the description the carrier used in shell or frame construction as individual components acts. Since these conventional carriers now completely by imaged the designed as an integral cast component structural body are, the term "load paths" is used above to a clear demarcation to ensure the multi-part designs.

As indicated above, on the other hand, a plurality of individual cast components to said rear carriage 2 be completed, with at least two main side members 5 . 6 by means of at least one front and one rear cross member 7 . 8th are connected together in the vehicle transverse direction.

Accordingly, the terms main longitudinal load paths and main longitudinal members as well as the terms front and rear transverse load path and front and rear cross member are used synonymously and accordingly with the same reference numerals 5 . 6 respectively. 7 . 8th Mistake.

Like that 1 and 2 can be seen further, in this case, the two transverse load paths or cross member 7 . 8th by means of two so-called auxiliary longitudinal load paths / auxiliary longitudinal members 9 . 10 firmly connected together, resulting in improved stiffening of the rear carriage 2 achieved and also supports 11 are created for various attachments of the chassis.

According to 2 have the main longitudinal load paths / main side members 5 . 6 of the back car 2 frontal surface receiving structures 12 . 13 on, which in turn are suitable, the bottom middle part 1 to record positively.

In the present case, the main longitudinal load paths / main longitudinal members are each 5 . 6 a recording structure 12 in the form of a closed end face and in the vehicle longitudinal direction extending receiving structures 13 provided, in turn, above and inside of the respective main longitudinal load path / main longitudinal member 5 . 6 are arranged and designed such that the bottom middle part 1 during assembly against the closed faces (Host structures 12 ) of the main longitudinal load paths / main longitudinal members 5 . 6 set and the reception structures 13 at least at the respective corresponding sill profile 4 can be fixed cohesively.

Put the case, it's like in 3 shown, a rear crash (force "F _HC ") recorded, so initially the transmission of the longitudinal loads via a positive connection of the components, in this case by a positive connection of the main longitudinal load paths / main side members 5 . 6 with the sill profiles 4 , in turn, on push at the main longitudinal load paths / main longitudinal beams 5 . 6 abutment and upwards and inwards ( 2 ) by means of the reception structures 13 are supported.

Furthermore, as a result of the rear crash (force "F _HC ") a moment load "M" of the adjacent components of the bottom middle part 1 and the back car 2 to record, which in turn requires a load-compatible connection of the same.

In extensive experiments it has now been found that connecting sections 14a between each main longitudinal load path / main longitudinal member 5 . 6 and at least the sill profile 4 of the bottom middle part 1 which are loaded in terms of a rear impact due to the respective force on pressure, simply and inexpensively by gluing 15 can be connected to each other. Such a connection section 14a is gem. 2 through the above-lying and in the vehicle longitudinal direction facing flat receiving structure 13 of the main longitudinal load path / main longitudinal member 5 . 6 realized, which accordingly by gluing 15 on the outer contour of the sill profile 4 is determinable.

In contrast, it has proven necessary to have connecting sections 16a between each main longitudinal load path / main longitudinal member 5 . 6 and at least the sill profile 4 of the bottom middle part 1 which are loaded with respect to said rear crash on train, by welding 17 to connect with each other. Such a welded joint is present in the lower connection region of the sill profile 4 to the respective corresponding main longitudinal load path / main longitudinal member 5 . 6 intended ( 2 and 3 ).

Even in the case of a side crash (force "F _SC ") a load-compatible connection of the respective main longitudinal load path / main longitudinal member 5 . 6 with at least the sill profile 4 to be able to guarantee, due to the applied moment load "M" on the outside of the main longitudinal load path / main longitudinal member 5 . 6 a claimed on train connection section 16b Accordingly, also by welding 17 is realized. The inside of the main longitudinal load path / main longitudinal member 5 . 6 arranged and pointing in the vehicle longitudinal direction surface receiving structure 13 can in contrast by gluing 15 on the outer contour of the sill profile 4 be established because this connection section 14b is claimed only on pressure ( 1 and 2 ).

Due to the load-friendly design of the connecting sections 14a , b, 16a , B or joints is an effective and defined transfer of crash loads in the adjacent module (Bodenmittelteil 1 Rear section 2 ) ensured by the weld produced in each case acts as a fixed bearing and thus the opposite bond seam is loaded on pressure. The per se known problem of peeling the bond line under unfavorable stress thereof does not occur by the above measures. Furthermore, a sufficient potential for tolerance compensation is given by said weld and adhesive seam, which has an advantageous effect on the production costs.

As in particular from the 1 and 4 Obviously, the floor profiles are based 3 of the bottom middle part 1 inter alia, at the front Querlastpfad 7 realizing structure or on the front cross member 7 of the back car 2 from and are firmly connected with this.

Said transverse load path / cross member 7 is presently formed by an angle profile, wherein a horizontal web thereof a surface portion 18 with elevations 19 and depressions 20 having. Said area section 18 is formed, so to speak wave or bead-shaped, whereby on the one hand an increased inherent rigidity of the transverse load path / cross member 7 achievable and the wall thickness thereof can be reduced within limits.

On the other hand, contact surfaces are created by this measure, which in a particularly advantageous manner, an optionally desired combination of bonding 15 and welding 17 allow. In this respect, it is considered appropriate that initially in the wells 20 Adhesive is introduced and subsequently the soil profiles 3 to the elevations 19 by means of tools known per se (contact pressure "P") and by welding, preferably spot welding, are firmly connected to the same.

If a thermosetting adhesive is used, it may be due to the weld 17 caused heat input to activate the curing process serve the same.

The weld 17 thus serves primarily to provide an initial strength of the composite to be achieved in the vehicle vertical direction (z-direction) and ensures a plan concerns the soil profiles 3 at said elevations 19 of the surface section 18 , By this measure is also effective a possible bending of the soil profiles 3 especially avoided in the vehicle longitudinal direction. Furthermore, in the area of the depressions 20 to record a defined or constant adhesive thickness, which in particular disadvantageous differences in strength of the joints are avoided.

Like that 1 and 4 can be further seen, are the soil profiles 4 from below against the horizontal web of the formed as an angle profile front Querlastpfades / cross member 7 set. However, it may also be indicated and is covered by the invention, said floor profiles 4 from above on the transverse load path / cross member 7 to set up and to connect with this firmly.

1

Floor center part

2

rear car

3

soil profile

4

sill profile

5

Main longitudinal load path / main longitudinal members

6

Main longitudinal load path / main longitudinal members

7

front Lateral load path / crossmember

8th

rear Lateral load path / crossmember

9

Auxiliary longitudinal load path / the auxiliary longitudinal member

10

Auxiliary longitudinal load path / the auxiliary longitudinal member

11

supports

12

receiving structure

13

receiving structure

14a, b

 connecting portion (Print)

15

splice

16a, b

 connecting portion (Train)

17

welding

18

surface section

19

increases

20

wells

Claims (8)

Floor assembly of a motor vehicle body, with a Bodenmittelteil ( 1 ) and a rear carriage ( 2 ), characterized in that the bottom middle part ( 1 ) of a plurality of juxtaposed and largely pointing in the vehicle longitudinal direction soil profiles ( 3 ) is formed, in turn, the body exterior side by a respective sill profile ( 4 ) are limited and the rear ( 2 ) is formed as an integral cast component or is completed from a plurality of individual cast components, wherein the bottom center part ( 1 ) and the rear carriage ( 2 ) are firmly connected to each other both positively and cohesively. Floor assembly according to claim 1, characterized in that the soil profiles ( 3 ) and sill profiles ( 4 ) of the bottom middle part ( 2 ) are formed as closed in cross section hollow sections, preferably continuous casting profiles. Floor assembly according to claim 1, characterized in that a trained as an integral cast component rear ( 2 ) is formed by a largely extending over the entire width of the vehicle body structure having at least two main longitudinal load paths ( 5 . 6 ) and a front and a rear transverse load path ( 7 . 8th ) realizing structures. Floor assembly according to claim 1, characterized in that the individual to a rear carriage ( 2 ) completed cast components at least two main side members ( 5 . 6 ) and a front and a rear cross member ( 7 . 8th ), wherein front and rear cross members ( 7 . 8th ) the main longitudinal members ( 5 . 6 ) connect in vehicle transverse direction with each other. Floor assembly according to one of claims 1 to 4, characterized in that the main longitudinal load paths / main longitudinal members ( 5 . 6 ) of the rear carriage ( 2 ) for the positive connection of the same to the bottom middle part ( 1 ) frontally one or more planar recording structures ( 12 . 13 ), which in turn at least at the corresponding sill profile ( 4 ) of the bottom middle part ( 1 ) are definable. Floor assembly according to one of claims 1 to 5, characterized in that connecting sections ( 14a , b; 16a , b) between the main longitudinal load path / main longitudinal member ( 5 . 6 ) and at least the sill profile ( 4 ) of the bottom middle part ( 1 ), which are subjected to pressure in view of a rear-end crash and / or a side crash as a result of the respective application of force, by gluing ( 15 ) are interconnected and connecting portions between the main longitudinal load path / main longitudinal member ( 5 . 6 ) and at least the sill profile ( 4 ) of the bottom middle part ( 1 ) subjected to tension in view of a rear crash and / or a side crash due to the respective application of force, by welding ( 17 ) are interconnected. Floor assembly according to one of claims 1 to 6, characterized in that the front transverse load path ( 7 ) realizing structure or the front cross member ( 7 ) a surface section ( 18 ) with elevations ( 19 ) and depressions ( 20 ) and the bottom middle part ( 1 ), at said area section ( 18 ), in the area of the formed elevations ( 19 ) by welding ( 17 ) and / or in the area of the depressions ( 20 ) by gluing ( 15 ) with the transverse load path / cross member ( 7 ) is firmly connected. Floor assembly according to one of claims 1 to 7, characterized in that the bottom middle part ( 1 ) and the rear carriage ( 2 ) consist of light metal, preferably of aluminum or magnesium.