DE102012008832A1 - Front structure for motor vehicle, comprises guide element supported on bumper cross beam through lever arm that is bumper bracket, whose upper end is elastically displaceable in vehicle longitudinal direction in event of collision - Google Patents

Abstract

The front structure comprises a body-mounted bumper cross beam (11), a bumper cover (1) covering the front side of the bumper cross beam and a radiator protective grille (3). A guide element (31) is directly supported on the bumper cross beam through a lever arm (33). The lever arm is a vertically mounted bumper bracket, whose lower end is rigidly fixed to the bumper cross beam, and whose upper end connected with the guide element is elastically or plastically displaceable in the vehicle longitudinal direction in the event of a collision.

Description

The invention relates to a front structure or a front end module of a motor vehicle according to the preamble of claim 1.

For improved pedestrian protection in the case of collisions, in particular in the lower speed range, deformation elements can be provided in the front structure of a motor vehicle, for example between the relatively soft, resilient bumper cover and the bumper cross member arranged behind it. However, depending on the construction of the stem of the vehicle, the pedestrian protection deformation elements are often not optimally positioned. In particular, the bumper cover and the radiator grille are rigidly connected to the plastic mounting bracket to ensure a uniform joint pattern at the transition between bumper cover and radiator grille. However, such a rigid connection is disadvantageous from the perspective of pedestrian protection.

From the DE 10 2008 048 039 A1 a generic front end structure of a motor vehicle is known which has a body-mounted bumper cross member and a front bumper cross member bumper covering the bumper cross member and a radiator grille. The bumper cover and the radiator grille are mounted on a rigid guide rail on the plastic mounting bracket, in a conventional manner even more attachments, such. B. carries a headlamp unit and radiator units.

The rigid connection of the bumper cover and the radiator grille results in a positionally accurate positioning with a corresponding uniform transition joint between the bumper cover and the radiator grille. This results in a rigid in the vehicle longitudinal direction in the event of a collision, unyielding structure and due to the cantilevered connection to the plastic mounting bracket unfavorable compliance in the vehicle vertical direction.

The object of the invention is to provide a front structure of a motor vehicle, in which can be improved with structurally simple, inexpensive means of pedestrian protection.

The object is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the subclaims.

The invention is based on the finding that milder from the DE 10 2008 048 039 A1 known connection of the guide rail on the mounting bracket in the pedestrian collision case excessively rigid component network is provided, so that additional measures to improve the pedestrian protection are required. In such a measure, the guide element itself can be provided with further deformation elements. According to the invention, however, the guide element is not provided with additional deformation elements per se, which is associated with an additional space requirement. Rather, according to the characterizing part of claim 1, the guide element is no longer supported directly on the mounting bracket, but via at least one lever arm directly on the bumper cross member. In the event of a collision, therefore, a force is transmitted to the guide element and thus the one or more lever arms loaded with a bending moment. In such a composite component according to the invention, therefore, the guide element can be deflected easier in the event of a collision to the rear.

According to the invention, therefore, a guide element connection with direction-dependent strength / compliance is provided. Under directional strength / compliance is to be understood that in normal driving the bumper cover and / or the radiator grille are sufficiently rigid component supported on the guide element, but in the event of a collision, the guide element in the vehicle longitudinal direction is designed to yield to the rear.

In this way, the guide element is designed in the normal driving in all spatial directions sufficiently rigid in order to achieve a visually perfect positioning of the bumper cover and / or the radiator grille. In pedestrian collision case, however, the guide element is designed to be compliant due to its connection to the underlying bumper cross member in the vehicle longitudinal direction, whereby the pedestrian protection is improved.

For a uniform energy distribution and energy absorption in the event of a collision and for a perfect positioning of the attachments, it is advantageous if the guide element is designed as a, in the vehicle transverse direction consistently over the entire vehicle width extending guide bar. This can preferably be supported on the bumper cross member via a plurality of lever arms spaced apart from one another in the vehicle transverse direction.

Preferably, the at least one lever arm in the vehicle vertical direction can be designed rigid and rigid and yielding in the vehicle longitudinal direction. By way of example, the lever arm can be an upright bending beam whose lower end is rigidly connected to the bumper cross member and whose upper, connected to the guide rail end in case of collision elastic or plastic can be displaced in the vehicle longitudinal direction.

The bumper cross member and the guide member may be arranged frontally in front of a frame-shaped plastic mounting bracket. At the plastic mounting bracket, the attachments of the stem structure are mounted in the correct position, such as a headlamp unit or a radiator unit. In contrast to the prior art, however, the guide element is entirely without direct connection to the mounting bracket, but rather in the vehicle transverse direction throughout a free deformation space spaced therefrom.

The bumper cover and the radiator grille may be two separate components. These can adjoin one another in the assembly position on mutually facing edge regions to form a transition joint. For a uniform joint pattern, the bumper cover and the radiator grille can also be connected via molded connection profiles with each other, for. B. connector, his. In a geometrically particularly simple plug connection, the connection profile of the bumper cover may have an integrally formed, groove-like receiving strip open at the front. This can be aligned horizontally and run in the vehicle transverse direction. In the receiving strip of the bumper cover, a corresponding edge web of the radiator grille may be inserted, which is formed at the lower edge region of the radiator grille.

For proper alignment, the connection profiles of the bumper cover and the radiator grille can also be supported on the body, on the above-mentioned guide member. For this purpose, the receiving strip of the bumper cover can be extended in the vehicle longitudinal direction to the rear by another edge web. The edge web can be inserted in a further plug connection with a corresponding groove-shaped recess of the guide element.

In general terms, for the correct positioning, the bumper cover and / or the radiator grille may have a mounting portion, such as a retaining web or edge web extending continuously in the vehicle transverse direction, which can be fastened directly to the guide element. The holding web can be an example in plug connection with a formed on the guide element mating contour. Optionally, the bumper cover and / or the radiator grille additionally be non-positively, material or positively connected.

To further improve the pedestrian protection can be arranged between the front end face of the bumper cross member and the bumper cover an additional deformation element. The additional deformation element may be formed of foamed plastic or thin-walled sheet metal profiles. Preferably, this additional deformation element extends continuously across the bumper cross member. The additional, arranged on the front side of the bumper cross member deformation element forms together with the arranged above the bumper cross member guide element a pedestrian protection system. These can be continuous in approximately parallel to each other in the vehicle transverse direction, so that in the event of a collision even more even energy distribution and energy absorption results. In addition, the additional deformation element together with the lever arm and / or the guide element form a structural unit or a pre-assembly unit. Particularly preferably, the additional deformation element and the at least one lever arm can be formed of the same material and in one piece as a deep-drawn sheet metal part or the lever arm z. B. be added by means of a welded connection on the deformation element. Alternatively, the lever arm may also be formed integrally with the bumper cross member or the guide element may be an integral part of the bumper cover or the radiator grille.

In a further embodiment, the guide element and the at least one lever arm of the same material and in one piece z. B. be made as a plastic injection molded component. In this case, the lever arm with its lower end z. B. are fastened via a screw on the bumper cross member or the deformation element.

In an alternative embodiment, the at least one lever arm can be embodied in two sections with a vertical leg in the vehicle longitudinal direction and a rear, inclined leg which converge on the guide element. The front vertical leg of the lever arm may be formed on the deformation element or the bumper cross member, while the rear lever arm leg z. B. can be connected to the upper edge flange of the bumper cross member.

It is essential that the connection of the guide element has a direction-dependent strength / compliance: Thus, the guide element in normal driving with the bumper weight be loaded. As a result, acts on the connection of the guide element in the direction of travel forward moment. In the event of a collision, however, the guide element is loaded with an impact force. This acts on the connection of the guide element in the direction of travel to the rear acting moment.

According to the invention, a stiffer connection is achieved in the direction of travel to the front by supporting the lever arm, as in the direction of travel to the rear during impact Accordingly, the moment due to the bumper weight forward are relatively stiff intercepted. This is achieved, for example, by an abutment, which is upstream of the guide element in the direction of travel. The abutment provides a support of the bumper weight in normal driving. By way of example, the abutment may be part of the bumper cross member.

When loading the guide element with the impact moment, however, a deflection of the lever arm against the direction of travel is comparatively easier. In this case, the lever arm can be deflected without hindrance to the rear against the direction of travel. The advantageous embodiments and / or further developments of the invention explained above and / or reproduced in the dependent claims can be used individually or else in any desired combination with one another, for example in the case of clear dependencies or incompatible alternatives.

The invention and its advantageous embodiments and further developments and advantages thereof are explained in more detail below with reference to drawings.

Show it:

1 a vertical longitudinal section through a front structure of a passenger vehicle with a bumper cross member, a bumper cover and a radiator grille and an overlying front flap;

2 in a perspective view from the front, the front structure without bumper cover and without radiator grille;

3 a view corresponding to the 1 on the basis of which a collision case is illustrated;

4 and 5 in each case further embodiments of lever arms of the transverse guide strip;

6 in a view from above, the front structure without radiator grille and without bumper cover;

7 and 8th in each case further embodiments of the invention; such as

9 and 10 a further embodiment of the invention in normal driving and in the event of a collision.

In the 1 is a front end structure or a front end module of a passenger car roughly schematically illustrated. The stem structure has in the vehicle longitudinal direction x front a bumper cover 1 and a radiator grille disposed above 3 on. At the lower edge area is the bumper cover 1 in an indicated sub-cladding 5 above. In the further course up closes to the radiator grille 3 an indicated front flap 7 on, on an upper cross bar of a frame-shaped plastic mounting bracket 9 is supportable. Behind the bumper cover 1 is a bumper cross member 11 arranged, at its two lateral ends over deformation consoles 13 fixed with side bulkhead plates 15 connected is. The bulkhead plates 15 are according to the 1 also on side rails 17 bolted to the front end structure of the motor vehicle.

The above-mentioned frame-shaped plastic mounting bracket 9 is at the two bulkhead plates 15 attached and carries attachments, such as the indicated dashed line radiator unit 19 or not shown headlight units.

The bumper cover 1 and the radiator grille 3 are mutually separate (not necessarily) components, the mutually facing edge regions to form a transition joint 4 ( 1 ) adjoin one another. For a uniform joint pattern are the bumper cover 1 and the radiator grille 3 via molded connection profiles 23 . 25 with each other in plug connection 26 ( 1 ). The connection profile 23 the bumper cover 1 is in the 1 for example, an integrally formed, forwardly open groove-shaped receiving strip 23 , which is oriented horizontally and in the vehicle transverse direction y. In the recording bar 23 the bumper cover 1 is a corresponding edge web 25 the radiator grille 3 plugged in, the at the bottom of the radiator grille 3 is trained. For a perfect alignment are the connection profiles 23 . 25 the bumper cover 1 and the radiator grille 3 supported on the body, on a trained as a guide rail guide element 31 , This is the recording bar 25 the bumper cover 1 according to the 1 in the vehicle longitudinal direction x to the rear another edge bridge 27 extended. The edge bridge 27 is in another plug connection 30 ( 1 ) with a corresponding groove-shaped recess 29 the guide bar 31 is plugged in. In addition, the connectors 26 . 30 be reinforced by other positive and / or non-positive and / or cohesive connection means.

The in the vehicle direction y transverse guide rail 31 is in the 1 exemplified by four upright, in the transverse direction y spaced lever arms 33 on the bumper cross member 11 supported. For this purpose, the lever arms 33 at the bottom 32 ( 1 ) to the front of a weight-supporting footprint on the rigid, such as by welding, on the bumper cross member 11 is connected. At the upper end, the lever arms 33 for example, by screw with the preferably made of plastic guide rail 31 be connected. In contrast to the prior art is therefore the guide rail 31 without direct connection to the mounting bracket 9 and forming a, in the vehicle transverse direction y continuous free deformation space 35 executed, as well as in the 2 . 3 or 6 is shown.

At his, the bumper cover 1 facing front, the bumper cross member 11 an additional deformation element 37 on, which may be a foamed plastic part or a thin-walled sheet metal profile part by way of example. The deformation element 37 runs in the vehicle transverse direction y continuously almost along the entire length of the bumper cross member 11 as it is in the 6 is shown. The additional deformation element 37 forms together with in the case of collision to the rear compliant guide rail 31 a pedestrian protection system, whose operation is described below on the basis of 3 is described.

Consequently, in the event of a collision, the impact impulse A acts both on the support strip 31 as well as on the additional deformation element 37 , As a result, in the event of a collision, a uniform energy distribution and energy absorption take place both at the deformation element 37 as well as on the guide rail 31 , The lever arms 33 the guide bar 31 namely, in the vehicle vertical direction z, although component-rigid, but in the event of a collision in the vehicle longitudinal direction x compliant formed. In this way acts on the guide bar 31 due to impact, a bending moment M ( 3 ), with which the guide bar 31 around the lower connection point 32 the lever arms 33 in the vehicle longitudinal direction x to the rear in the free deformation space 35 can be deflected. The lever arms 33 thus each form bending beams, with their lower end 32 are firmly connected to the body, but with their upper end in the event of a collision elastic or plastically resilient are deflectable. The compliance of the lever arms 33 is specifically tailored to the pedestrian protection requirements across the entire width. At the same time, however, a stiff support of the bumper weight and thus a perfect joint pattern is ensured in normal driving.

In the 4 and 5 are each further embodiments of the connection of the guide rail 31 on the bumper cross member 11 shown. So is in the 4 the deformation element 37 a U-shaped thin-walled sheet metal part, the bumper cross member 11 is welded. The deformation element 37 consists essentially of an upper and a lower, horizontally oriented leg 41 . 42 and a vertical base section 43 together. According to the 4 goes the upper leg 41 at a transitional edge 44 in an upwardly angled lever arm 33 above. The lever arms 33 and the deformation element 37 form in the 4 thus a unit of material and integral unit. Alternatively, in the 5 the lever arms 33 and the bumper cross member designed as a unitary and one-piece unit. The bumper cross member 11 is also a U-shaped profile sheet metal part with an upper and a lower, approximately vertical edge flange 47 , The upper edge flange 47 of the crossbeam 11 is according to the 5 upwards with a lever arm 33 extended.

In the 7 are in a further embodiment, the guide bar 31 and the lever arms 33 made of the same material and in one piece as a plastic injection-molded component. According to the 7 are the lower ends of the lever arms 33 via a screw connection 49 at the upper edge flange 47 the bumper cross member 11 attached. Alternatively, in the 7 shown lever arm 33 also on the deformation element 37 be connected.

In the 8th is the lever arm 33 two-legged with a front vertical leg 51 and a rear slanted leg 53 Running on the guide rail 31 converge. The front vertical leg 51 is at the deformation element 37 molded, while the rear leg 53 at the upper edge flange 47 of the bumper cross member 11 is connected.

Generally speaking, it is essential that the binding of the guide rail 31 has a direction-dependent strength / compliance, the following example by way of 9 and 10 However, it can also apply to all other embodiments of the invention:
So is in the 9 the lever arm 33 with its lower foot on the lower leg of the cross member 11 by welding 39 attached. Of the crossbeam 11 is in the 9 an example of a U-shaped, open to the rear hollow profile. The lever arm 33 is on the edge flange 47 the upper cross-member leg passed and loose with this in Appendix. In addition, the lever arm protrudes 33 the top of the cross member 11 with a given distance.

In the 9 the arrangement is shown in normal driving, in which the guide rail 31 is loaded with the weight F _{G of} the bumper. This acts on the lever arm 33 the guide bar 31 a moment M _G , which is directed forward in the direction of travel. The loaded with the moment M _G lever arm 33 is at the edge flange 47 supported by the upper cross member leg. This therefore acts as an abutment, which is a bending of the lever arm 33 prevented to the front. The abutment thus provides an additional support of the bumper weight forward.

In the 10 a collision case is shown, in which the guide rail 31 loaded with an impact force F _A. This acts on the lever arm 33 the guide bar 31 a moment M _A , which acts in the direction of travel to the rear. In this case, the lever arm can 33 bend without hindrance to the rear against the direction of travel, thus avoiding the lever arm 33 is comparatively easier. This Wesie results in a common deformation of the guide rail 31 as well as the bumper cover 1 and the radiator grille 3 ,

It is therefore according to the invention in the direction of travel forward a stiffer connection by a support of the lever arm 33 achieved at an abutment, as in the direction of travel to the rear on impact, so that the moment M _G is caught relatively stiff due to the bumper weight forward. When loading the guide rail 31 with the impact moment M _A , however, a deflection of the lever arm 33 comparatively easier.

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

• DE 102008048039 A1 [0003, 0007]

Claims (10)

Front structure of a motor vehicle, with a body-mounted bumper cross member ( 11 ) and a bumper cross member ( 11 ) front covering bumper cover ( 1 ) and / or a radiator grille ( 3 ) located on at least one, in the vehicle vertical direction (z), preferably above the bumper cross member (z) ( 11 ) arranged guide element ( 31 ) can be positioned in the correct position, characterized in that the guide element ( 31 ) via at least one lever arm ( 33 ) directly on the bumper cross member ( 11 ) is supported. A front structure according to claim 1, characterized in that the lever arm ( 33 ) is an upright bending beam whose lower end ( 32 ) rigidly on the bumper cross member ( 11 ) and its upper, with the guide element ( 31 ) connected end in the event of a collision elastic or plastic in the vehicle longitudinal direction (x) is displaced. A front structure according to claim 1 or 2, characterized in that the guide element ( 31 ) as a in the vehicle transverse direction (y) is preferably continuous over substantially the entire width of the vehicle guide rail, in particular over a plurality of, in the vehicle transverse direction (y) spaced from each other lever arms ( 33 ) is supported. A front structure according to claim 1, 2 or 3, characterized in that the lever arm ( 33 ) in the vehicle vertical direction (z) component rigid and in the vehicle longitudinal direction (x) is designed yielding. Front structure according to one of the preceding claims, characterized in that the bumper cross member ( 11 ) and the guide element ( 31 ) at the front in front of a mounting carrier ( 9 ) for attachments, in particular for a cooler unit ( 19 ), and that in particular between the guide element ( 31 ) and the mounting carrier ( 9 ) in the vehicle transverse direction (y) continuously free deformation space ( 35 ) without direct connection of the guide element ( 31 ) on the mounting bracket ( 9 ) is provided. A cowl structure according to any one of the preceding claims, characterized in that an upper edge region of the bumper cover ( 1 ) and a lower edge region of the radiator grille ( 3 ) forming a transition joint ( 4 ), in particular via connection profiles ( 23 . 25 ), are connected. Front structure according to one of the preceding claims, characterized in that the bumper cover ( 1 ) and / or the radiator grille ( 3 ) a mounting portion ( 27 ), in particular a holding web, which on the guide element ( 31 ) is attachable. Front structure according to one of the preceding claims, characterized in that between the bumper cross member ( 11 ) and the bumper cover ( 1 ) an additional deformation element ( 37 ) is arranged, which together with the resilient in the event of a collision guide ( 31 ) provides a uniform-collision energy distribution and absorption and / or that the deformation element ( 37 ) continuously transversely along the bumper cross member ( 11 ) runs. A front structure according to claim 8, characterized in that the cross member ( 11 ) together with the lever arm ( 33 ) and / or the guide element ( 31 ) forms a structural unit or pre-assembly unit and that in particular the cross member together with the lever arm ( 33 ) is formed of the same material and in one piece. A front structure according to claim 8 or 9, characterized in that the guide element ( 31 ) together with the lever arm ( 33 ) forms a structural unit or pre-assembly unit and that in particular the guide element is formed together with the lever arm of the same material and in one piece.

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