DE102013207236A1 - Front bumper assembly for vehicle e.g. motor car, has upper and lower cross beams connected with vehicle frame through leg portion, and specific material weakening point provided at junction of lower cross beam and leg portion - Google Patents

Abstract

The bumper assembly (2) has upper and lower cross beams (3,4) that are connected with vehicle frame (5) through U-shaped lateral leg portion (6). A specific material weakening point having energy absorption function is provided at the junction of lower cross beam and lateral leg portion. The specific material weakening point is extended in vehicle longitudinal direction. A bolt is penetrated between the lateral leg portion and vehicle frame.

Description

The invention relates to a bumper arrangement for a vehicle, in particular a motor vehicle, with at least one bumper cross member arranged in the vehicle end area.

Bumper assemblies must meet a variety of requirements. So they have to provide a good energy absorption both in the event of a crash at low and at high speeds and to protect the rest of the vehicle as possible from damage. It is u. a. necessary to design the rigidity of the bumper assembly and the overlap of the bumper assembly with the obstacle in the event of a collision (crash) as large as possible. This can be achieved in particular by a selection of stiff cross member profiles and high height in the vehicle vertical direction.

It is also important to meet the high demands of modern crash tests (eg Euro Ncap). In most tests, the vehicle is driven against a stationary deformable barrier that only partially covers the front of the vehicle. The barrier should simulate a hit vehicle. In order to achieve a good crash suitability of the vehicle, it is important to convert a lot of kinetic energy of the vehicle into deformation work of the barrier. By a relatively large overlap of the impact area of the vehicle, so the bumper assembly, with the barrier, the penetration depth can be positively influenced.

Also, the installation dimensions of the bumper assembly should be as small as possible in order to allow effective space utilization (packing) in the vehicle.

In addition, optical and aerodynamic reasons play a not insignificant role in the size of the bumper assembly. Thus, the smallest possible overhang of the bumper assembly is desired forward over the wheels for reasons of styling (styling).

In addition, the bumper arrangements should afford good protection in the event of collisions with pedestrians, for which it is useful to provide special pedestrian-protecting parts (eg foam), which should be accompanied as far as possible without additional space requirements. These parts (e.g., foam) usually have a non-compressible content when they collide with a passer or specimen. This non-compressible portion should be integrable into a bumper.

It can be seen that the different requirements contradict each other in the necessary characteristics of space utilization, stiffness, energy absorption, the largest possible height, small packing dimensions, optics, etc.

The EP 1 347 892 B1 describes a bumper beam assembly in which the tubular, tapered crash boxes collapse together in an axial collision, reducing their overall depth while expanding their overall width or circumference to form a U-shaped cross member profile into which they protrude , bend and flatten. Thus, it is less likely that the cross member penetrates deep into the rest of the vehicle. By bending the rigidity of the U-shaped cross member is greatly reduced.

From the EP 1 604 869 B1 For example, a bumper beam assembly is known in which a second impact absorbing structure is carried by one part of the engine mount, whereby the second impact absorbing structure is separated from the others and their absorption direction is separable.

In addition, it would be desirable if the bumper support assembly would be easily adaptable to different legal security requirements of the respective sales region and at the same time a repair would be simplified.

The object of the invention is therefore to provide a bumper beam assembly that is adaptable to different legal security requirements by exchangeable parts.

This object is achieved by the reproduced in claim 1 bumper beam assembly.

According to the invention, it has been recognized that when the bumper cross member is detachably connected to the vehicle frame and for energy absorption in the event of impact has a point targeted material weakening, the impact absorbing properties are adaptable. This can be done by changing the location of targeted material weakening. Since this part is interchangeable, a part adapted to the respective safety requirements can be used depending on the region.

Preferably, the bumper cross member is U-shaped and connected via the lateral legs to the vehicle frame, wherein the lateral legs each have the point targeted material weakening. It thus extends in a known manner approximately across the vehicle width and then angles in the vehicle longitudinal direction in each case from the outside. These legs are then connected to the vehicle frame and each have the point targeted material weakening. Thus, the impact energy acting in the vehicle longitudinal direction is absorbed there.

It is particularly useful if the point targeted material weakening at the junction of the bumper cross member is arranged with the vehicle frame. Thus, it is possible to design the bumper cross member or the point targeted material weakening for low impact speeds and to replace after damage. The point of targeted material weakening is pushed together. In a high-speed impact, a stable U-shaped cross member is formed, which is "shortened" around the point of targeted material weakening.

If the site of targeted material weakening is designed so that the connecting means between the lateral leg and the vehicle frame in the event of an impact energy-absorbing penetrates into the site of targeted material weakening, the function for low impact speeds can be carried out particularly easily.

Structurally, this function can be easily implemented when, the point of targeted material weakening connects to the hole for the connecting means. Then the bonding agent can penetrate directly into the site of material weakening.

Alternatively, the location of targeted material weakening may be in close proximity to the bore for the connectors. For example, a slot may be arranged as a location of targeted material weakening immediately adjacent to the bore, separated from the bore by a remaining web. In the case of an impact, this web is first destroyed, and then only penetrates the connecting means in the place of targeted material weakening. This allows a controlled breakaway force to be achieved in order then to deform the bumper assembly in a defined load level.

As connecting means are bolts, screws, rivets, etc. into consideration, with which the cross member is detachably connected to the vehicle frame.

It is particularly useful if the point targeted material weakening extends in the vehicle longitudinal direction.

The point targeted material weakening may be in preferred embodiments, either a reduced in width over the connecting means slot or a reduced thickness in the material strip.

Further features and details of the invention will become apparent from the following description of the drawing. Show it:

1 a schematic perspective partially sectioned view of a bumper assembly in the front area of the vehicle in the normal state;

2 the arrangement 1 after a low to medium speed impact and

3 a schematic exploded view of the junction between the inventive cross member and vehicle frame.

In the figures one is as a whole with 1 designated vehicle 1 with a front bumper assembly 2 shown.

The bumper arrangement 2 has an upper cross member 3 and a lower cross member 4 which is the subject of the invention.

The upper cross member 3 is directly with the vehicle frame 5 (H-frame) connected or included in this.

The lower cross member 4 is U-shaped and over the lateral legs 6 with the vehicle frame 5 via subcarrier 7 connected.

It thus extends in a known manner approximately across the vehicle width and then angles in the vehicle longitudinal direction in each case from the outside.

These thighs 6 are then with the vehicle frame 5 via subcarrier 7 connected and each have a job 8th targeted material weakening on. Thus, the impact energy acting in the vehicle longitudinal direction is absorbed there.

The spot 8th targeted material weakening is at the junction of the bumper cross member 4 or the thigh 6 with the subcarrier 7 arranged. Thus, it is possible the bumper cross member 4 or the job 8th targeted material weakening designed for low impact speeds and to replace after damage. The point of targeted material weakening is pushed together (cf. 2 , respectively. 3 Arrow). In a high-speed impact, a stable U-shaped cross member is formed, which is "shortened" around the point of targeted material weakening.

The spot 8th targeted material weakening is designed such that the connecting means (bolts 9 ) between the lateral legs 6 and the subcarrier 7 in the event of an impact energy absorbing in the place 8th targeted material weakening penetrates (cf. 2 , respectively. 3 Arrow).

The spot 8th Targeted material weakening follows the hole 10 for the bolt 9 at. It extends in the vehicle longitudinal direction and is considered to be one in width opposite the bolt 9 or the corresponding hole 10 reduced slot formed.

The bolt 9 extends the impact virtually the slot (point 8th ) and thereby destroys energy or the slit allows the uniform deformation on impact until it is "used up" and so a stable U-shaped cross member, which is "shortened" to the point of targeted material weakening (see above). This is the thigh 6 in the spar 11 of the subcarrier 7 inserted.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1347892 B1 [0008]
• EP 1604869 B1 [0009]

Claims (8)

Bumper arrangement for a vehicle, in particular motor vehicle, with at least one arranged in the vehicle end region bumper cross member, characterized in that the bumper cross member is detachably connected to the vehicle frame and has a point targeted material weakening for energy absorption in the event of an impact. Bumper arrangement according to claim 1, characterized in that the bumper cross member is configured U-shaped and is connected via the lateral legs to the vehicle frame, wherein the lateral legs each have the point targeted material weakening. Bumper arrangement according to claim 1 or 2, characterized in that the point of targeted material weakening at the junction of the bumper cross member is arranged with the vehicle frame. Bumper arrangement according to claim 3, characterized in that the point targeted material weakening is designed such that the connecting means between the lateral leg and the vehicle frame in the event of an impact energy-absorbing penetrates into the point targeted material weakening. Bumper arrangement according to claim 4, characterized in that the point of targeted material weakening connects to the bore for the connecting means. Bumper assembly according to claim 4, characterized in that the point of targeted material weakening connects in close proximity to the bore for the connecting means. Bumper arrangement according to one of claims 4 to 6, characterized in that the point of targeted material weakening extends in the vehicle longitudinal direction. Bumper arrangement according to one of the preceding claims, characterized in that the point of targeted material weakening is a reduced in width with respect to the connecting means slot or a reduced thickness in the material strip.

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