DE4228472A1 - Impact absorber for vehicle and for packaging and transporting - has cellular construction insert of metal foil, covered in porous cladding and snapped to fit space around item to be protected - Google Patents

Abstract

The cellular structure is made from metal foil and has a cell shape designed to absorb impacts in the expected directions. The cells are rectangular and can be curved around fittings. The metal wall thickness to cell length ratio is between 1:10 and 1:20. Aluminium or steel is used and secured by adhesive, electric welding etc.. The structure is covered with a porous cladding to prevent compression of trapped air on impact. Shaped sections replace damping layers and supplement shock absorbing layers in a vehicle. For packaging the structures are designed to fit around objects on pallets etc.. USE/ADVANTAGE - Impact absorbtion layers in vehicle, protective packaging for hazardous materials etc.. Increases accident safety.

Description

The invention relates to a shock absorber Improve accident safety and reduce the Crash sequences preferably used in motor vehicles all kinds.

In addition, with the use of such shock absorbers About the consequences of an accident or the impact of a crash on a stationary patient and mobile constructions as well as plants the.

A reliable solution to this problem is acute Transport, storage and operation of dangerous or highly endangered goods, in the housing, changing room Formation or lining of containers with dangerous in hold, such as acids or fuel up to for the protective covering of nuclear reactors.

There are various solutions for the automotive industry Structure of bumpers and energy absorbers known. The manufacturers use shock absorbers, the sudden loads more or less uniaxial convert into plastic deformation.

DE 28 53 244 describes a bumper for motor vehicles, described in particular motor vehicles. It is about To motor vehicles with a rigid, in vehicle solid parts support, the one made of foamed Material existing, preferably by an elastic Apron-covered energy absorber is upstream.  

As an essential feature of this invention, bean says that the deformation resistance of the energy absorber bers, starting from the center of the bumper, in the direction the bumper ends by changing the foam density and / or continuous or gradual due to material weakening wise decreases.

Such a preferably regenerable energy absorber About, partly from a tough elastic material existing shell is surrounded, is in DE 31 25 687 further educated that the real energy absorber is arranged close to the joint and its movement or Load is coupled with locking elements.

From DE 33 45 408 a shock absorber is known, the one Has molded body and in particular for installation between the bumpers and the body or the chassis is provided. The molded body consists of a Flake composite foam of certain density.

DE 38 36 724 describes an impact damper for compliant the bumper is attached to the side member of a vehicle Tool construction with a working cylinder and one in it displacement displacing a medium Pushing piston having shock absorber, the from the Working cylinder protruding displacement piston forehead tig carries a bracket for attaching the bumper.

Furthermore, it is an impact absorber with a housing partially accommodating the working cylinder, a device for attachment to the side member points, and of an energy arranged in the housing has absorbent deformation member on which the Working cylinder with its facing away from the bumper  Supports end face.

Finally, with DE 39 25 821 one with an energy pre-absorbing foam filled energy absorber public, the opposite of the shock attack Wall section at least one with a defined opening te provided opening through which already together pressed foam with a further increase in force Energy absorption is squeezed, the opening only upon reaching a predetermined force level is created that a weak point of the Wall section bounded area is separated.

Generally for use in automotive engineering notice that apart from at least two stiff Points that are constructive in the immediate Area behind the license plate where the crash zone begins, much softer cavity is given away.

Derived from the prior art, it is the task of Invention to develop a shock absorber with which the Crash resilience of vehicles as well as to be protected Systems or objects while ensuring a reliable protective effect is increased in which the occurring Interference energy at the immediate point of action, i.e. in the fore field of the objects to be secured is dismantled.

In addition, sudden loads in several Axis directions can be converted into plastic deformation can.

An inventive solution to this problem is in the patent claim 1 specified. Developments of the invention are characterized in the subclaims.  

The essence of the invention consists in cavities or in free spaces between units in motor vehicles in Front, rear and side areas as well as for cladding or lining of objects to be protected Materials to three-dimensional shock-absorbing space formed to process or in existing geometri to adapt to the conditions. That arises in this way existing shock absorbers should be as light as possible and have low costs.

The shock absorbers according to the invention consist of metal foils lien or sheets, which are profiled and to a flat, single or double curved grate in three-dimensional Spatial expansion are added that depend on the done Profiling and the subsequent layering and connection of the profiled foils or sheets a variety of Space cells are created.

The cross-section of the cells forming the grate hangs depending on the type of profiling of the metal foils or sheets.

Optimal conditions with regard to energy absorption of the shock absorber, the conversion of impact energy into pla There is a static deformation when the profiling and joining against the metal foils or sheets so that the Space cells have a square cross section. Each Deviation from the square cross-sectional shape is with Losses in the work or power absorption capacity of the Shock absorber connected. This effect is special even with single or double curved versions of the Shock absorber with the loca inevitably present here len deviations from the desired square space cross-section.  

The profiling of the metal foils or sheets can be done with for example by folding or deep drawing. Of the Joining process of the profiled foils or sheets can u. a. by gluing or tailing and in particular which is realized by electrical resistance welding become.

The profiling itself is as rectangular as possible, where for flat room cell arrangements or gratings parallel edge guidance is given. For simply curved ones Systems where the direction of the radius of curvature is the direction of the longitudinal cell longitudinal axis z per cell level matches, the edge spacing will change in the direction the common center or the perpendicular through the Center of each longitudinal plane axis of the protected object, depending on the radius of curvature of the Reduce rust. For double in the x and y directions curved systems can also pass through the second radius of curvature the different degrees of pushing the ge Layered profiled metal foils can be set.

The direction of loading of the shock absorber coincides with that Axis direction of the room cells forming the shock absorber match. It follows that for multi-axis loads Combinations of differently oriented Raumzel units must be provided.

To set favorable mass-performance ratios the room cell structure, the grate preferably made of aluminum produced.

The preferred film or sheet thickness is in the range 0.1 to 2 mm.  

Of course, for such uses as cover of stored dangerous goods, highly explosive Production sites such as nuclear reactors u. at the. even bigger ones Sheet thicknesses and other materials are used.

For the area of application in automotive engineering, the above Values, i.e. aluminum with a thickness of 0.1 to 2 mm.

The associated side lengths of the square cells lie preferably in the range 1.5 to 30 mm and the spatial expansion of the grate in the direction of the cells longitudinal axis is about 5 to 100 mm.

For those who know the stability, the ability to work drawing relation of thickness of the used metal fo lines or sheets to the edge length of the room cell cross a favorable value range from 1:10 to 1:20 found.

The open space cells should expediently be permanent be covered, one of the covers being perforated or must be permeable to compressed air. This is guaranteed ensures that the enclosed and possibly compressed Air can escape.

Essential for dimensioning and using the shock absorber bers is that in its stiffness the stiffness of the to be protected zone can be adapted.

It should also be noted that the shock according to the invention absorber was initially designed as a passive damping element and statically tested as a voluminous load-bearing con structure can be used.

The aluminum takes pressure in the longitudinal direction of the cell  the greatest possible plastic deformation work on.

In automotive engineering at the appropriate points or the required such protection zones arranged a few kilograms are sufficient, to also meet perspective security requirements gene.

This mass can certainly be found elsewhere (load bearing Parts, sheet thickness, sound insulation paste u. a.m.) saved become.

In addition to automobile construction, an important field of application is the Shock absorber to protect objects or systems Transport, storage and operation of dangerous or objects at risk of impact.

The shock absorber is also successful in personal protection can be used, for example in a double curved version for lining or cladding (motorcycle) protective helmets men.

The invention is hereinafter without limitation general inventive concept based on exemplary embodiments play exemplary with reference to the drawing to the rest of the disclosure all of the invention not explained in detail in the text Details are expressly referred to. Show it:

Fig. 1, the energy absorption diagram of a shock absorber according to the invention,

Fig. 2 shows a detail of a planar shock absorber rust,

Fig. 3 shows the structure of the spatial units,

Fig. 4 shows the illustration of a quarter sector of a cylindrical shell, the cut Behäl ters,

Fig. 5 is a protective helmet jacket.

Fig. 1 illustrates the energy absorption capacity of the shock absorber according to the invention with a square cell cross section.

Typical curves for the absorption of plastic work W _{p are shown} based on 1 gram for different materials and room cell dimensions. The evaluation limit in FIG. 1 with = 0.5 is set arbitrarily.

The shock absorber work W _p was determined by measurement for various film or sheet thicknesses and for various relations between material thickness and edge length of the space cell cross section for a given sample height (spatial extension z).

The examined samples are dimensioned as follows:

• for the curve W _p1 :
• - Aluminum used
• - film thickness 0.275 mm
• - Edge length 2.5 mm
• - sample height 15 mm
• for the curve W _p2 :
• - Steel used
• - film thickness 0.185 mm
• - Edge length 2.5 mm
• - sample height 15 mm
• for the curve W _p3 :
• - Steel used
• - film thickness 0.095 mm
• - Edge length 2.5 mm
• - sample height 10 mm.

The shock absorber work performed is applied over the Degree of deformation, expressed by the ratio current Deformation density to the final density of the deformation.

It can be seen that with a uniform Edge length of the square space cell cross section of 2.5 mm the comparatively best results regarding work done by the shock absorber with the material Aluminum in the specified geometry can be achieved.

A section of a flat shock absorber grate 1 , as can be used for example in automobile construction, is shown in FIG. 2.

The direction of loading 3 and the object 4 to be protected are shown.

This grate 1 consists of a plurality of room cells 2 with a square cross-section as possible, which are formed by meandering profiling of aluminum foils, their subsequent layering and contacting.

Fig. 3 shows this Entstehungsweg from the metal foil 5 to the absorber grate 1. The connection of two profiled aluminum foils is made at the edges 6 by gluing.

Fig. 4 shows the casing of a cylindrical container age, for example for the transport and storage of dangerous goods by a simply curved shock absorber. In the illustrated embodiment, the expected loading direction 3 extends radially, perpendicular to the longitudinal axis of the cylindrical protected object.

Double, d. H. Shock absorbers curved in the X and Y directions can be dome-shaped or dome-shaped, for example be educated.

In Fig. 5 is a doubly curved shock absorber system is shown to the protective helmet shell. The longitudinal axes of the room cells 2 all run perpendicular to the protective helmet base body; thereby the shock absorber in the load directions 3 has the maximum energy absorption capacity.

Claims (11)

1. Shock absorber to increase the safety against accidents and to reduce the consequences of a crash, particularly in motor vehicles, characterized in that metal foils and / or sheets ( 5 ) are profiled and subsequently to a flat or single or double curved in the X and Y directions rust ( 1 ) are joined in three-dimensional spatial expansion, that the grate consists of a large number of room cells ( 2 ) with any cross-section dependent on the type of profiling. 2. Shock absorber according to claim 1, characterized in that for multi-axis stresses gratings ( 1 ) or cells ( 2 ) differently aligned spatial axes are combined with one another, grids with different spatial cell cross sections can be connected in series in each axial direction. 3. Shock absorber according to claim 1 or 2, characterized in that aluminum foils or sheets with a wall thickness of 0.1 to 2 mm are preferably used for the construction of the grids ( 1 ) or cells ( 2 ). 4. Shock absorber according to one of claims 1 to 3, characterized in that the metal foils and / or sheets ( 5 ) are profiled meandering as possible at right angles and that the resulting spatial cells ( 2 ) preferably have a square cross-section. 5. shock absorber according to claim 4, characterized in that the side lengths of the Raumzel lenquads for the area of application of the shock absorber for  Motor vehicles are preferably 1.5 to 30 mm and the spatial expansion of the grate in the direction of the cell longitudinal axis lies in the range of approx. 5 to 100 mm. 6. Shock absorber according to one of claims 1 to 5, characterized in that the dimensioning of the room cells ( 2 ) defining the ratio of the thickness of the inserted metal foils ( 5 ) or sheets to the edge length of the room cell cross section preferably the value 1:10 to 1: 20 has. 7. shock absorber according to one of claims 1 to 6, characterized in that the rust-like, permanent open cell arrangement on the front is covered, one of the end covers perforated or at least permeable to compressed air is. 8. shock absorber according to one of claims 1 to 7, characterized in that the joining of the profiled Metal foils or sheets by gluing or welding, preferably electrical resistance welding is carried out. 9. shock absorber according to one of claims 1 to 8, characterized in that its stiffness, its ar absorption capacity of the stiffness of the to be protected Zone is adjusted. 10. shock absorber according to one of claims 1 to 9, characterized in that it is a passive damping element ment, but also as a voluminous load-bearing construction is settable.   11. Shock absorber according to one of claims 1 to 10, characterized in that its area of application generally the protection of dangerous or endangered goods in the warehouse, Transport and operating process includes the pallet the objects to be protected or the configuration of the Shock absorber from a suitably designed motorcycle helmet a casing of containers with dangerous contents up enough to cover nuclear reactors.