DE10123479A1 - Impact damping front hood for a vehicle comprises a deformation structure in the form of deformation cups which are attached to the inner sheet of the hood - Google Patents

Abstract

The impact damping front hood for a vehicle comprises a deformation structure in the form of deformation cups (3.1, 3.2, 3.3) which are attached to the inner sheet (2) of the hood, and are capable of absorbing energy.

Description

The invention relates to an impact-absorbing front hood for a vehicle for recording impact energy caused by a pedestrian or other person involved in the impact, in particular also by a simulating the impacting head of a pedestrian Impactor is introduced.

The severity of injuries, especially head injuries, to pedestrians or other parties involved in the impact, whose head collides with the vehicle in the event of a collision Bonnet opens, bonnet constructions have become known, which in can absorb and reduce predetermined areas particularly impact energy. The areas are covered with impact devices with a pedestrian's head simulating impactors determined by impact tests in which the impactors with certain speed shot at the predetermined areas and the relevant geometric and material parameters of the bonnet using a optimal deceleration course can be evaluated. To reduce the so-called Head injury criterion HIC (Head Injury Criterion) must be met during the collision the impact energy introduced into the impactor in a known manner corresponding to a ideal curve of acceleration over time (a-t curve) largely eliminated the curve based on a calculation based on the amount Impact energy that must be absorbed in the collision is based. The essential relationships are shown in DE 195 14 324 A1. In this Scripture describes a hood that has an upper outer panel (top plate) Inner sheet and a so-called shock absorber or impact absorber (Deformation structure) to absorb the impact that is caused by the top plate Impactor exercised and by which this is deformed, and which with a so-called. Impact body (engine, strut supports) corresponds to this in the event of an impact staying. The energy absorption rate is the deformation structure and a Total hollow gap formed between the top plate and the impact body is so determined that the impact energy introduced during the impact corresponds to the  ideal acceleration (a) - time (t) curve can be recorded around the Head injury criterion HIC with the shortest possible stroke (smallest possible Deformationsweg) to reduce the top plate, so that the distance of the Upper plate to the impact body can be kept small. In the Scriptures are about that numerous designs of bonnets are described, the deformation structure also by several impact receiving bodies and also by one of longitudinal and Cross bars formed inner sheet can be formed. The structure of the bonnets is while consuming.

Furthermore, it is known from DE-A-20 61 623, in particular in the field of Arrange vehicle doors plastically deformable deformation members, which are preferred consist of sheet metal and can be stepped and which by a Upholstery are covered.

Furthermore, it is known from EP 0 683 072 B1, a between the outer sheet Vehicle body and an interior panel so-called shock absorber made of dimensionally stable pressed fiber material in the form of a step pyramid (terrace arrangement) for Use impact reduction, which occurs in a side impact as a result of this shear force occurring deformed. The steps form individual shear force zones, between which energy-consuming bending or folding processes and finally Shear processes are running.

It is an object of the invention to provide an impact-absorbing front hood for a vehicle to design the preamble of claim 1 so that its structure is less expensive is.

This task is performed with an impact-absorbing front hood according to the generic term of Claim 1 solved by their characteristic features. advantageous Refinements are listed in the subclaims.

The invention is that in an impact-absorbing front hood, which an upper plate and an inner plate forming a stiffening structure and a deformation structure is formed, the latter with only a small gap on vehicle-fixed support surfaces, in particular on the drive unit and on Vehicle body and body parts given support surfaces, which is formed  Deformation structure from the inner sheet on the side facing away from the upper sheet in Distance arranged deformation pots is formed, which is substantially perpendicular are deformable to absorb energy to the top plate. The thickness of the Gap essentially only the usual installation tolerances that are in the drive unit are determined by its movement during operation. The thickness of the between The hollow gap given to the top plate and the supporting surfaces can be reduced so far be that through an impactor or the head of a pedestrian or other Impact participants brought into the front hood impact energy with an optimized Deceleration curve (a-t curve) is converted, the top plate and the Deformation pots located locally on the inner sheet largely impact energy take up. The head injury criterion HIC is reduced.

In a preferred embodiment, the inner sheet and the deformation pots integrally formed. The one-piece is technologically and technically assembly by Advantage. This design allows the production of the stiffening structure forming inner sheet with the deformation structure in just one step (Deep drawing). In addition, the use of materials can be reduced.

Depending on the arrangement of the unit and the support surfaces in the engine compartment and the shape of the stiffening structure are the deformation pots on the corner and Crossing points of the same arranged. By arranging and distributing the Deformation pots in connection with the design of the stiffening structure, also in the With regard to their sheet thickness, the Front hood, in particular in a so-called. Child's head impact area and a so-called adult head impact area, different HIC values can be realized.

The deformation pots preferably have the shape of rotationally symmetrical hollow bodies or of hollow bodies with a square or polygonal cross section, the Cross-sectional area decreases with increasing distance from the top plate. In particular, however, these are terraced pyramids or Truncated cones. However, they can also be constricted in shape Cylinders or a negative barrel shape. You can also use plastic, preferably PUR or PP, exist and can be retrofitted.  

Furthermore, in or in predetermined deformation pots Foam elements or deformation bodies, for example also with one Honeycomb structure made of plastic, be arranged in addition to the in the event of an impact Deformation elements absorb impact energy. As an energy absorber Foams are suitable for solid, closed-pore or open-pore PUR or PP Foams. With such a foam, the deformation elements can also be foamed. In this way, the front hood can be different Set different HIC values for ranges.

The invention is explained below using exemplary embodiments. In the associated drawings show schematically:

Fig. 1 is a bottom view of an impact absorbing bonnet,

Fig. 2 shows a section II-II through them,

FIGS. 3a-c show different forms of deformation pots and

FIGS. 4a-f variants of Innenblech- or bonnet designs.

The front hood shown in FIG. 1 is formed from an upper plate 1 and an inner plate 2 connected to it and forming a stiffening structure, with deformation pots 3.1 . The inner panel 2 has the stiffening structure transverse and longitudinal bars 4 and 5 trough-shaped cross-section, which form a frame which is connected on its outer edges to the top plate 1 in a known manner and which is in the middle between the two longitudinal bars 5 by a third cross bar 4 is reinforced. The deformation pots 3 are integrally formed in the area of the four frame corners and in the middle of the central cross member 4 on the inner sheet 2 or the bows 4 , 5 forming this, as hollow bodies open on the sheet metal side. These each have the shape of a terrace-shaped truncated pyramid with a square cross-section, in which the end face 6 formed at the tapered end serves as a baffle face 7 for a support surface (11, FIG. 2) given under it in the event of an impact by an impact party. The inner plate 2 is connected to the upper plate 1 in the region of the inner bow edges and at the middle deformation pot 3.1 by an adhesive layer 8 ( FIG. 2). Instead of the truncated pyramid-shaped deformation cups 3.1 , which are shown enlarged in FIG. 3a, the deformation cups 3.2 and 3.3 shown in FIGS . 3b and 3c, of which the one shown in FIG. 3.2 has the shape of a rotationally symmetrical truncated cone and that in FIG shown. 3.3 in the form of a rotationally symmetrical, necked hollow cylinder.

In Fig. 2 the front hood is shown in section II-II between the fenders 10 connected to the upper side members 9 . In this section, the arrangement of the deformation pots is seen over 3.1 arranged in the engine compartment of the vehicle-fixed support surfaces 11, which impingement surfaces are arranged 7 in only a small distance above the support surfaces. 11 The middle support surface 11 is provided by the drive unit 12 and the two outer support surfaces 11 by the strut mountings 13 .

In FIGS. 4a to 4f are shown further embodiments of a bonnet, wherein the dashed lines correspond to the course of the inner panel 2 forming bows show trough-shaped cross-section. In each embodiment, the corner points of the stiffening structure formed by the inner sheet 2 and the intersection points or starting points of the bow within the frame formed by the longitudinal and cross bow 5 or 4 are provided with a deformation pot 3 , also shown in broken lines.

LIST OF REFERENCE NUMBERS

1

upper sheet

2

inner panel

3.1

deformation pot

3.2

deformation pot

3.2

deformation pot

4

crossbeam

5

Längsspriegel

6

face

7

baffle

8th

adhesive layer

9

longitudinal beams

10

fender

11

support surface

12

power unit

13

MacPherson strut

Claims (7)

1. Impact-damping front hood for a vehicle with an upper plate and an inner plate forming a stiffening structure and a deformation structure which is formed with a small gap above vehicle-fixed support surfaces, characterized in that the deformation structure on the inner plate ( 2 ) facing away from the upper plate ( 1 ) Side spaced-apart deformation pots ( 3.1 , 3.2 , 3.3 ) is formed, which are deformable to absorb energy substantially perpendicular to the top plate ( 1 ). 2. Front hood according to claim 1, characterized in that the deformation pots ( 3.1 , 3.2 , 3.3 ) are an integral part of the inner panel ( 2 ). 3. Front hood according to claim 1 or 2, characterized in that the deformation pots ( 3.1 , 3.2 , 3.3 ) are arranged at corner and crossing points of the stiffening structure. 4. Front hood according to one or more of the preceding claims, characterized. characterized in that the deformation pots ( 3.2 , 3.3 ) are rotationally symmetrical hollow bodies or hollow bodies with a square ( 3.1 ) or polygonal cross-section, the cross-sectional area of which decreases with increasing distance from the top plate ( 1 ) and which have an impact surface ( 7 ) at their tapered end. 5. Front hood according to one or more of the preceding claims, characterized in that the deformation pots ( 3.1 ) have the shape of a terrace-shaped truncated pyramid. 6. Front hood according to claim 1, characterized in that the deformation pots ( 3.1 , 3.2 , 3.3 ) made of plastic, preferably PUR or PP. 7. Front hood according to one or more of the preceding claims, characterized in that the or predetermined deformation pots ( 3.1 , 3.2 , 3.3 ) are filled with a solid, deformable open-cell or closed-cell foam, in particular made of PUR or PP, or that in the or predetermined deformation pots ( 3.1 , 3.2 , 3.3 ) deformation bodies are arranged.