DE102004024578B4 - An energy absorbing composite beam of a vehicle structure of a vehicle and method of manufacturing the same - Google Patents

Abstract

An energy composite beam a vehicle structure of a vehicle, in particular front or rear side member or Crashbox of a motor vehicle, with an outer and a covered by this, radially spaced inner support, their space with foamed, both carriers force fit filled in capturing plastic characterized in that the inner support (2) is at a first end the outer support (1) is assigned such that it is in an impact in one of the two along the carrier (1, 2) opposite directions at the same time and to the same extent together with the outer support (1) the impact energy is exposed while he is on his second End distance opposite the impact zone of the local end of the carrier (1) has, wherein the inner carrier (2) independent at its first end from the outer support (1) and the between these two carriers (1, 2) located, foamed plastic is mounted on the vehicle structure.

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 preambles of claims 1 and Second

In such an off DE 199 34 666 A1 known composite carrier form inner and outer support at their ends no abutment with respect to a Aufprallenergieaufnahme- or support. As a result, no optimal, independent energy absorption function can be exerted by the inner support.

Out AT 334 221 B is an energy-absorbing composite support with an inner and outer support and provided therebetween plastic foam known in the inner and outer wearer have the same length. In this embodiment, therefore, the entire structural component deforms in an impact in the longitudinal direction over the entire length in the same way energy-absorbing.

For a composite beam after US 5,992,923 A in which plastic foam is provided between an outer and inner shell, these two shells are also formed the same length. Furthermore, the inner shell is there via the outer shell, with which it is connected via the plastic foam located between this, attached to a vehicle support structure, that is, it lacks an independent connection between the inner shell and support structure.

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 shape different designed interior support can be influenced. In particular, a graded in the longitudinal direction Energy absorption behavior of the composite support can be achieved.

Is solved this problem in a generic composite support by An education according to the characterizing features of the claim 1.

One Particularly advantageous and convenient method of a generic composite support is Subject of claim 2.

Of the internal support serves additionally to its function as a boundary wall for the introduced between the two carriers Plastic foam as an independent Energy absorber. Therefor is the inner carrier stored in the outer support such that Impact energy after first only a deformation of the outer carrier directly on both carriers at the same time and to the same extent can act. For this purpose, both carriers should, when deformed together are each at both ends impact energy regardless of the plastic foam filling transferred to outer abutment. A particular advantage of the invention is existing support structures in particular longitudinal members and crash boxes of vehicles unchanged to be able to use and yet this through differently designed and stored Interior carrier 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.

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 5 such that the inner carrier 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, own constantly 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 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.

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 (2)

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, comprising an outer and a radially spaced from this, inner carrier whose space is filled with foamed, both carrier positively locking plastic, characterized in that inner carrier ( 2 ) at a first end of the outer support ( 1 ) is assigned in such a way that upon impact in one of the two along the carrier ( 1 . 2 ) in opposite directions simultaneously and to the same extent together with the outer support ( 1 ) is exposed to the impact energy, while at its second end distance from the impact zone of the local end of the carrier ( 1 ), the inner support ( 2 ) at its first end, independent of the outer support ( 1 ) and between these two institutions ( 1 ; 2 ), foamed plastic is mounted on the vehicle structure. Process for producing an energy-absorbing composite support according to claim 1, characterized in that the inner support ( 2 ) to which the plastic to be foamed ( 3 ) is already applied, independently of the outer support ( 1 ) on the vehicle structure ( 4 ) is stored.