DE102009023534A1 - Body component, particularly engine hood, has outer skin, substructure and energy absorption element between outer skin and substructure, where energy absorption element is arranged in edge area of body component - Google Patents

Abstract

The body component has an outer skin (3), a substructure (2) and an energy absorption element between the outer skin and the substructure. The energy absorption element is arranged in the edge area of the body component. The energy absorption element has a deformation element, which is available in the form of a profile rail.

Description

The The invention relates to a body part with an outer skin and a substructure, in particular a bonnet.

conventional Front door designs are usually on a large scale Self-rigidity of the flap with respect to a bend and a twist designed for low weight. This happens z. B. by means of a strongly profiled substructure, which material and / or form-fitting connected to an outer skin. This substructure is usually stiffened by additional components. The Outer skin is as large as possible supported by this rigid substructure to a Prevent bumps or flutter. These front flaps meet the licensing requirements of the European Union and / or Test criteria according to EuroNCAP with respect to a head impact insufficient because they are usually too stiff or too hard.

For example EP 1 093 980 A1 relates to a bonnet for motor vehicles, which has a deformable head impact zone for the protection of pedestrians in a collision with the motor vehicle, wherein the bonnet is constructed of two or more supporting shells. At the edges of the bonnet has a low bending stiffness, while this increases steadily towards the center. At the same time, the bonnet has a homogeneous mass distribution over the entire surface. This should be achieved regardless of the location on the hood everywhere the same characteristics for the head impact. The design of the hood provides a reinforcing plate with regularly arranged beads, with at most three beads form a node to reduce local stiffness. Another bonnet is in US 2006/0163915 A1 disclosed.

Out DE 100 37 628 A1 For example, an engine hood is known which is provided with an energy absorbing material, wherein the energy absorbing material is arranged to abut portions of the hood in which, statistically, a very large number of people impinge on the engine hood due to a collision is and is tuned to located in an engine compartment components. It should be in the areas of the hood, in which statistically proven with high relative frequency a standard pedestrian in a collision with a vehicle incident, better energy absorption than in the other areas in which the pedestrian usually does not hit. It should be noted in particular that the attachment of the energy-absorbing material is also adapted to located under the hood components. It is disadvantageous that different impact properties thus result for different, even central, regions of the engine hood. Also, the energy absorbing material can wear comparatively easily in direct proximity to the engine compartment. In addition, between the bonnet and the components located in the engine compartment sufficient for insertion of the energy absorbing material distance must be maintained, which makes a compact design difficult. Another device for reducing personal injury with a located between the body and a hard component energy-absorbing adapter is in WO 2007/02791 A1 described.

DE 10 2005 033 949 A1 discloses a bonnet made of composite material for motor vehicles consists of an outer skin, inner cover layers and in between core parts made of hard foam or honeycomb. In order to meet the requirements of both collision types (in this case vehicle, as pedestrian) with simple production and low weight, the core parts form zones of different hardness and / or thickness. Furthermore, a predetermined bending zone is provided across the entire width of the hood, which is achieved by weakening the structure. The nominal buckling zone is the boundary between a front zone with softer core parts and a rear zone with higher strength core parts. This is disadvantageous, for example, that the entire bonnet must be placed consuming the core parts. In addition, even a small impact can permanently deform a core part, after which the engine hood must be replaced.

It The object of the present invention is a compact, wear-susceptible and in many areas substantially uniform impact protection especially for pedestrians, which is also simple and a low impact Energy survives substantially unscathed.

These Task is performed according to the characteristics of the independent Claim solved. Preferred embodiments are in particular the dependent claims removable.

The Task is solved by means of a body part, which Outer skin, a substructure and at least one energy absorbing element between the outer skin and the substructure. The at least one energy absorption element is at an edge region arranged the body part.

This body part makes use of the knowledge that a kinetic energy of an impact of an object (eg a pedestrian, cyclist, etc.) on the outer skin of the body part by the at least one energy absorption element may be at least partially received before the object impinges on underlying hard components (substructure, engine block, generator, etc.). The fact that the energy absorbing element is housed in a typically existing space between the outer skin and the substructure, no distance between the body part and underlying components need to be provided, which allows a compact design.

The Body part makes further use of the knowledge that the at least one energy absorbing element is not between the body part and the underlying hard parts needs to be arranged to dampen the impact. Rather, in a crash on a lying next to the energy absorbing element area of Outer skin of the outer skin are pressed and exercises thereby stressing the energy absorbing element. One such stress may be due to a loose resting of the outer skin For example, include a pressure load, in a mechanical solid composite of the outer skin with the energy absorbing element also a tensile load and / or a compressive load. At a high enough Strain, the energy absorbing element will be under absorption at least part of the kinetic generated during the impact Deform energy. Thus, the fact that the at least one energy absorption element is arranged in an edge region of the body part, a large inner area are generated, in which an object is not directly impinges on the energy absorbing element. Under a border area In particular, an area can be understood which is located in the Essentially on an outer third, in particular an outer quarter of a lateral or lateral Extension of the body part limited. This in turn can also be a more wear-resistant positioning (eg away from a hot engine block) and a versatile one Design of the energy absorption element allows. Furthermore, a wide range can be substantially uniform acting impact protection be provided as an impact in an area within the peripheral areas (an inner area) based on a same deformation characteristic and, for example essentially independent of a location from below the outer skin lying hard components is. In addition, can a slight impact on the inner area by an elastic Deformation of the outer skin can be cushioned without the body part already harmful to it.

Under An edge region can also be understood as an area which itself from a geometrical subdivision of the front surface of a motor vehicle according to EuroNCAP. In the EuroNCAP test becomes the front surface of the motor vehicle to be examined mentally divided into several rows of several test fields each, and these test fields can be used individually or in groups compliance with certain criteria. In particular, an area can be understood as an area which are at least the two outermost ones Test series of an impact test, in particular the EuroNCAP test, the front flap includes. Specifically, under a border area Be understood area, which only the utmost Test field series of the front flap includes.

From The border area may also include an area which is at Front flaps known as the side rail profile and which represents the area to the lateral joint. The energy absorption element can thus in particular on the side rail profile be attached.

It may be an embodiment that all energy absorption elements are arranged in an edge region of the body part. This can created a single, especially large inner area become.

The Energy absorption element may be the kinetic generated in the impact Transform energy in a basically arbitrary way or absorb, for. B. by an elastic deformation, an elastic-plastic Deformation, a substantially plastic deformation, a destruction (z. Cracking), a volume change, a pressure change, a phase transformation, a transformation into heat, etc.

It may be an embodiment that at least one energy absorption element at least one deformation element (often called 'defoelement') includes. The deformation element can the kinetic energy of the Impact in a mechanical, in particular substantially plastic, Convert deformation. A deformation element has the advantage on that it can be simple, cheap and stable Materials can be constructed and before a deformation or in the normal (not deformed) state usable as a stable structural element is. In addition, a deformation behavior of the deformation element is good predictable, z. B. by means of a finite element analysis.

The deformation element can be produced according to a further development of metal. A good compromise between sufficient stability in the normal state and a good deformation characteristic can be obtained, for example, by means of a steel sheet, a thickness between 0.5 mm and 1.5 mm or an aluminum sheet having a thickness between 0.5 mm and 2 mm. However, the material is not limited to a metal, especially can z. B. also include plastic.

The Deformationselement may according to yet another Training in the form of a rail present. A profile rail is easy and inexpensive and also easy to produce.

It can still be a development that the deformation element at least one extending in a longitudinal direction Bending edge, wherein the deformation element in a deformation bent at least along the at least one bending edge.

It may be an embodiment that the rail is a cross-sectional shape having at least one inclined portion, wherein the inclined portion at its respective ends each with a bending edge with at least one other Section is connected. An advantage of this embodiment is that the rail is both under a laterally directed, deformed at the other sections attacking tensile load (such it can occur in an impact on the inner area), as well as under a thrust acting pressure load (as in a collision on the outer skin above the deformation element can occur).

The Cross-sectional shape of the rail, for example, at least partially "Z" -shaped, being the sloping section and one each with it at one end subsequent further section a bending angle more than 90 ° each.

The Cross-sectional shape of the rail can alternatively be an oblique standing section and thus each subsequent to one end Section having a bending angle of less than 90 ° ("Oblique step").

however the shape of the rail is not limited to this. The cross-sectional shape of the rail, for example, also 'hat-shaped' be configured, which consists of two mirror-symmetrical Profiles of the form of a sloping step composed.

Also For example, a 'C' profile or a 'W' profile can be used.

Further a deformation element can also have a plurality of profile rails, z. B. two side by side and / or successively arranged rails. The profile rails can have different profile shapes exhibit.

Furthermore can be a rail for adjusting its deformation characteristics Have stiffeners and / or recess and / or wavy and / or discontinued.

It may be a training that at least one deformation element rigid in longitudinal direction (longitudinal beam stiff) is executed. This can be a change in shape the outer skin under different low loads (Wind, body twisting, etc.) are counteracted. Especially can then be a lateral joint (the Strak) be designed so that she does not open up.

The Energy absorption element can in a training in the normal State a structural element, in particular a spacer, between the substructure and the outer skin. This is a particularly compact and simple construction of the body part possible.

It can still be a development that the outer skin with the substructure in a limited by the at least one energy absorbing element Inner area via at least one resilient support element firmly or loosely connected. This support element causes the Advantage that the outer skin in the normal state of the vehicle can remain largely dimensionally stable while the support elements In a collision, a deformation of the outer skin is not significantly hamper. In other words, the support elements be designed so that they contribute to the dimensional stability of the outer skin are sufficiently stiff, but on the other hand are so soft that they a deformation of the outer skin in an impact not significantly hamper.

It may still be a development that the support element a open area of the substructure at least partially surmounted. So can compared to a body of a body part with a conventional, relatively stiff substructure and First, the outer skin is comparable to a normal one sufficient dimensional stability of the outer skin ensured Second, there in a collision, a touchdown on the harder Substructure can be avoided and thirdly a weight savings be enabled. The substructure therefore refers to the outer skin stiffer areas (especially in the edge area), and in the form of the at least one support element on the stiffer Area subsequent comparatively soft elements.

It may also be a further development that the at least one support element has at least one bending element that projects away from the substructure and that is bent in the direction of the outer skin. This flexure may be an integral part of the substructure. A bending element is mechanically easy to handle, simple and inexpensive to manufacture bar and also from a variety of materials (metal, plastic) to produce.

The Bending element, for example, one of a stiffer area be the substructure of outgoing curved free beams. however it is to ensure only a small deformation of the bending element under normal conditions advantageous if the at least one Support element arcuate on both sides of the substructure going on. In other words, the bending element can then be considered a two-sided on the substructure clamped in the direction of the outer skin be executed curved beam.

It may be a training that at least one energy absorption element at a respective (with respect to a longitudinal extent the vehicle) lateral edge region is arranged. This is a particularly high energy absorbing element usable whereby a particularly high energy absorption is achieved.

It may also be a development that at least one energy absorption element at one (with respect to a longitudinal extent of the Vehicle) front edge region is arranged.

It can also be an embodiment that the at least one a lateral edge region arranged energy absorbing element and the at least one arranged on a front edge region energy absorption element are designed differently. This can cause a deformation the outer skin adapted to a predetermined impact situation be, and the shape of the body part can easily to a desired shape be adjusted.

It can also be an embodiment that the body part a Front flap is, in particular a hood. This can be a use The method described above on a front flap a particular enable good protection of a pedestrian. However, the invention is generally not for use with limited to a front flap, but can also be at others Body parts are used, for. B. on a tailgate, etc.

In The following single figure, the invention with reference to an embodiment described in more detail schematically. It can for clarity identical or equivalent elements with the same reference numerals be provided.

1 shows an oblique view of a partially cut bonnet;

2 shows a deformation element of the hood 1 ,

1 shows an oblique view of a body part in the form of a partially cut bonnet 1 a motor vehicle with a substructure 2 and one the substructure 2 covering outer skin 3 , At a right side edge area of the substructure seen from the front 2 is a lateral energy absorbing element in the form of a lateral deformation element 4 attached; mirrored is at a left side edge area of the substructure 2 a lateral deformation element (not shown) attached. The lateral edge area is z. For example, an area that is in the outermost test field when using the EuroNCAP test. The lateral edge region can in particular on the profile carrier area 15 the hood 1 be attached. At a front edge area of the substructure 2 is a front energy absorption element in the form of a front deformation element 5 attached. 2 shows the lateral deformation element 4 more detailed as a separate component.

Referring to the following 1 and 2 have the lateral deformation element 4 and the front deformation element 5 a different shape and deformation property. So that's the front deformation element 5 much flatter than the lateral deformation element 4 to a tapered bonnet 1 to enable.

Both deformation elements 4 . 5 are intended to be used in the event of an impact of an object on the bonnet 1 To convert kinetic energy occurring in a substantially plastic deformation and thus at least partially absorb the impact. This is, for example, the lateral deformation element 4 have been bent out of a stamped sheet metal profile, one of the substructure 2 protruding sloping section 6 is directed obliquely inwards. This sloping section 6 goes to the substructure 2 towards an angled lower support surface 7 over and to the outer skin 3 into an angled upper support surface 8th , The lower support surface 7 is with the substructure 2 firmly connected, and the upper bearing surface 8th is with the outer skin 3 firmly connected. The bending edges between the inclined section 6 and the lower bearing surface 7 and between the sloping section 6 and the upper bearing surface 8th each have a bending angle of less than 90 °. The shape of the cross section of the deformation element 4 can thus also be referred to as an oblique step. The sloping section 6 has different recesses over its length 13 and striving 14 to set the desired deformation behavior and to save weight. The deformation element 4 can also various stiffening gene, settlements, etc. have. In particular, the deformation element is very longitudinally rigid, which allows a very good shape and shape retention of the front flap in normal operation.

In an inner area, which through the deformation elements 4 . 5 is limited, the substructure indicates 2 a front open area 9 and a rear open area 10 on. The rear open area 10 is two arcuate from the substructure 2 curved in the direction of the outer skin and outgoing in their direction support elements 11 spans. In the middle of the support elements 11 There is a support surface (not shown) for supporting the outer skin 3 , In a mounted state of the outer skin 3 This is thus firstly on an outer edge 12 the substructure 2 second, on the deformation elements 4 . 5 (in the case of the lateral deformation element 4 for example, on the upper support surface 8th ) and thirdly with substantially punctiform contact surfaces on the two support elements 11 ,

In a normal operation one with such a bonnet 1 equipped motor vehicle remains the shape of the outer skin 3 essentially unchanged, since, among other things, the support elements 11 prevent significant deformation, for example, at high speeds and / or in a torsion of the body.

In the event of a collision with the center of the bonnet 1 on which typically a torso and / or a head of a pedestrian on the hood 1 bounces, first the outer skin 3 bent in the direction of the substructure. The deflection of the outer skin 3 is through the support elements 11 not significantly impeded. Due to this deflection, the outer skin tightens 3 also in the edge regions and thereby exerts a burden on the serving as a spacer deformation elements 4 . 5 out. So is on the upper support surface 8th applied a load which the upper bearing surface 8th pulls inside. As long as the deflection of the outer skin 3 is low, the deformation elements 4 . 5 not deformed yet. This will avoid the entire bonnet 1 due to a deformation of the deformation elements 4 . 5 even with very small deformations of the outer skin 3 must be replaced.

With progressive bending of the outer skin 3 is the on the deformation elements 4 . 5 applied load so large that these deformation elements 4 . 5 deform substantially plastically, which absorbs impact energy and the impact is attenuated. This is how the deformation elements become 4 . 5 bent at their bending edges with a reduction of the bending angle.

In case of an impact on an edge area of the bonnet 1 above a lateral deformation element 4 This is so yielding that it is also deformed. For example, the deformation element 4 are also bent along its bending edges with a reduction of the bending angle in such a direct impact due to the pressure load occurring thereby. Thus, even with an impact in the lateral edge region of the hood 1 adequate impact protection is maintained.

Due to the distance of the outer skin 3 from the substructure 2 or the relatively stiffer areas of the substructure 2 without the support elements 11 For example, a comparatively high energy can be absorbed before sitting on a stiff or hard volume. As a result, excellent pedestrian protection can be provided even at low impact speeds without impairing a protective effect at higher impact velocities.

All in all is a high flexibility in pedestrian protection and flap stiffness achieved. Through an individual adaptation of the deformation element to the respective front flap can the head impact requirements implemented with very high rigidity become.

Of course the present invention is not limited to the embodiment shown limited.

1

Engine Hood

2

substructure

3

shell

4

lateral deformation element

5

front deformation element

6

aslant standing section

7

lower bearing surface

8th

upper bearing surface

9

front open area

10

rear open area

11

support element

12

outer edge the substructure

13

recess

14

strut

15

Profile support region

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1093980 A1 [0003]
• US 2006/0163915 A1 [0003]
• - DE 10037628 A1 [0004]
• WO 2007/02791 A1 [0004]
• DE 102005033949 A1 [0005]

Claims (14)

Body part ( 1 ) comprising an outer skin ( 3 ), a substructure ( 2 ) and at least one energy absorption element ( 4 . 5 ) between the outer skin ( 3 ) and the substructure ( 2 ), wherein the at least one energy absorption element ( 4 . 5 ) at an edge region of the body part ( 1 ) is arranged. Body part ( 1 ) according to claim 1, wherein the at least one energy absorbing element ( 4 . 5 ) at least one deformation element ( 4 . 5 ). Body part ( 1 ) according to one of the preceding claims, in which the deformation element ( 4 . 5 ) in the form of a profile rail ( 4 . 5 ) is present. Body part ( 1 ) according to claim 3, wherein the deformation element ( 4 . 5 ) has at least one longitudinally extending bending edge, wherein the deformation element ( 4 . 5 ) bends at a deformation at least along the at least one bending edge. Body part ( 1 ) according to claim 4, wherein the profile rail ( 4 . 5 ) a cross-sectional shape with at least one inclined portion ( 6 ), wherein the inclined portion at ( 6 ) its respective ends in each case via a bending edge with at least one further section ( 7 . 8th ) connected is. Body part ( 1 ) according to claim 5, wherein the cross-sectional shape of the profile rail ( 4 . 5 ) the inclined portion ( 6 ) and the subsequent at each end further section ( 7 . 8th ) having a bending angle of less than 90 °. Body part ( 1 ) according to one of the preceding claims, in which at least one energy-absorbing element ( 4 . 5 ) is designed rigid. Body part ( 1 ) according to one of the preceding claims, in which the energy-absorbing element ( 4 . 5 ) a structural element, in particular a spacer, between the substructure ( 2 ) and the outer skin ( 3 ). Body part ( 1 ) according to one of the preceding claims, in which the outer skin ( 3 ) with the substructure ( 2 ) in one of the at least one energy absorption element ( 4 . 5 ) limited inner region via at least one resilient support element ( 11 ) connected is. Body part ( 1 ) according to claim 9, wherein the at least one support element ( 11 ) at least one of the substructure ( 2 ) outgoing, towards the outer skin ( 3 ) bent bending element ( 11 ) having. Body part ( 1 ) according to claim 10, wherein the at least one support element ( 11 ) arched from the substructure ( 2 ) goes off. Body part ( 1 ) according to one of Claims 9 to 11, in which the support element ( 11 ) an open area of the substructure ( 2 ) at least partially surmounted. Body part ( 1 ) according to one of the preceding claims, in which at least one energy-absorbing element ( 4 ) at a lateral edge region of the body part ( 1 ) is arranged. Body part ( 1 ) according to one of the preceding claims, in which the body part ( 1 ) is a front door, in particular a hood, is.