DE102004024578A1 - Energy absorbing laminate beam for motor vehicle structure, especially front or rear side member of crushing zone, has inner holder provided within outer holder and has one end exposed opposite to direction of impact - Google Patents

Abstract

An outer holder (1) and an inner holder (2) are joined to a vehicle structural part such as a front panel (4) or side member. A synthetic foam (3) is filled between the holders. One end of the inner holder is exposed opposite the direction of impact, such that when impact acts on both holders, both deform equally in opposite directions. An independent claim is also included for a production method of an energy absorbing laminate beam.

Description

The The invention relates to an energy absorbing composite carrier Vehicle structure of a vehicle and a method for its Production according to the preamble of patent claim 1.

Such a composite carrier is made DE 199 34 666 A1 known. In this composite beam, inner and outer beams at their ends do not necessarily form common abutments with respect to impact energy absorption or support. As a result, no optimal, independent energy absorption function can be exerted by the inner support.

The Invention busy dealing with the problem of providing a generic composite support, its energy absorption function to a greater extent than previously by material and formally different designed interior support can be influenced.

Is solved this problem in a generic composite carrier in the first Line by training according to the characterizing features of Patent claim 1.

Appropriate and advantageous embodiments and a preferred method for Production or assembly of a composite carrier according to the invention are Subject of the dependent claims.

The Invention is based on the general idea, the inner support in addition to its function as a boundary wall for the introduced between the two carriers Plastic foam as independent To use energy absorber. For this purpose, the inner support is so stored in the outer support, that impact energy directly on both carriers at the same time and in the same Dimensions can interact. For this purpose, it is particularly advantageous if both carriers on both Ends impact energy regardless of the plastic foam filling transferred to outer abutment can. A particular advantage of the invention is existing support structures such especially longitudinal beams and Crash boxes of vehicles unchanged to be able to use and yet this through differently designed and stored internal support depending on the application, different Gesamtdeformationsverhalten impose.

Advantageous, in more detail below explained embodiments The invention are shown in the drawing.

In show this:

1 a longitudinal beam in composite construction in longitudinal section,

2 the side member after 1 in a state of deformation after an impact,

3 a longitudinal member with a connected crash box in longitudinal section,

4 the side member after 3 in deformed condition after an impact.

A side member after 1 includes an outer support 1 and only over a partial length of the outer wearer 1 extending inner beams 2 , Both carriers 1 . 2 are radially spaced from each other so that there is an annular space between them through a fiber-reinforced plastic foam 3 is filled.

The basic material of the plastic foam 3 is in the not yet foamed state on the inner support 2 , The foaming takes place in a state in which both carriers 1 and 2 are fully assembled, by heat, as obtained, for example, in a cathotic dip painting (KTL) of a vehicle with an inventively designed longitudinal beam anyway.

At the in 1 example shown is the one from the carriers 1 and 2 formed as a composite part longitudinal member on the end wall 4 attached to a vehicle. The attachment is for example via a plug connection such that the inner support 2 on the front wall 4 at a time when on this carrier 2 applied base material for the foaming plastic is not yet foamed, independently on the front wall 4 is fixed. Independently fixed here means that in this state no support on the outer support 1 must be present. As a result, a simple assembly is possible. The front wall 4 exercises in a crash accident in particular the function of an abutment in relation to the out of the carriers 1 and 2 existing composite part.

The deformation of the longitudinal member after 1 in a longitudinal impact shows the 2 , By forming only an axial portion as a composite support a stepped deformation behavior of such a longitudinal member is possible. While in a first deformation stage only the longitudinal region, which is not formed as a composite carrier, deforms like a fold and thus shortens, the part designed as a composite region initially remains undeformed. The reason for this is that, with respect to this range, deformation strain requires a higher strain energy. The amount of this deformation energy can be achieved by different internal supports 2 with unchanged outer supports 1 vary in a simple way. Of course, the range of variation is also determined by the selection and the configuration of the plastic to be foamed 3 with determined. By the between the carriers 1 and 2 foamed plastic creates a sandwich-like composite part.

According to the embodiment 2 form an outer vehicle 1' and an inner carrier 2 ' through a plastic foam 3 ' connected a crash box in composite construction. This crash box is fixed to a side member 6 connected to a vehicle. The inner carrier 2 ' is firmly connected to abutment at both ends. One of these abutments 7 is one end plate of the crashbox, while the other abutment 8th a partition between the side member 6 and the crashbox with the outer and inner beams 1' . 2 ' is.

A deformed state of the crash box after 3 show the 4 ,

The inner carrier 2 ' serves as the inner carrier 1 in the execution after 1 for receiving the not yet foamed plastic of the plastic foam 3 , Even with the crash box, the inner support can be independent of the outer support during assembly 1' on the partition 8th between the longitudinal member 6 and the crashbox are fixed in position.

Important for an inventive optimal function of the composite support is in each case a support of the inner support member 2 . 2 ' on the vehicle structure in order to allow the inner carrier to be effective as a fully effective, self-contained deformation element.

Claims (4)

Energy-absorbing composite support of a vehicle structure of a vehicle, in particular front or rear side member or crash box of a motor vehicle, with an outer and one of these encompassed, radially spaced inner carrier whose space is filled with foamed, both carrier positively locking plastic, characterized in that the inner Carrier ( 2 . 2 ' ) at least at one of its ends the outer support ( 1 . 1' ) is assigned in such a way that, at least in the case of an impact in one of the two, it slides along the support ( 1 . 2 ) in opposite directions simultaneously and to the same extent together with the outer support ( 1 . 1' ) is exposed to the impact energy. An energy absorbing composite support according to claim 1, characterized in that the inner and outer supports ( 1 . 2 ; 1' . 2 ' ) are associated with each other at both ends such that at least in one of the two opposite directions along the carrier ( 1 . 2 ; 1' . 2 ' ) at the one end, by both institutions ( 1 . 2 ; 1' . 2 ' ) simultaneously and equally absorbed impact energy from both carriers ( 1 . 2 ; 1' . 2 ' ) at the other end of the plastic foam filling ( 3 ) independent abutments ( 4 . 7 . 8th ) is transmitted. Energy absorbing composite body according to claim 2, characterized in that the respective abutments ( 4 . 7 . 8th ) the carrier ( 1 . 2 ; 1' . 2 ' ) are directly or indirectly connected to the vehicle structure. Process for producing an energy-absorbing composite support according to claim 1, characterized in that the inner support ( 2 . 2 ' ) to which the plastic to be foamed ( 3 ) is already applied, independently of the outer support ( 1 . 1' ) on the vehicle structure ( 4 . 8th ) is stored.