DE102009021281A1 - Bumper arrangement for motor vehicle, has bumper element movably arranged in vehicle longitudinal direction, and control device selectively transferring element into basic position and into drive position depending on speed of vehicle - Google Patents

Abstract

The arrangement (10) has a bumper element e.g. lower bumper (20), movably arranged in a vehicle longitudinal direction. A control device selectively transfers the bumper element into a basic position and into a drive position depending on speed of a motor vehicle (12). The bumper element is tiltably or pivotably supported around an axis running parallel to a vehicle vertical axis. The bumper element is protruded in its drive position. The bumper element is movable by mechanical, electromechanical, hydraulic or pneumatic switch units and/or resetting units between the basic and drive positions. An independent claim is also included for a method for controlling a bumper arrangement.

Description

The The present invention relates to a bumper assembly for a motor vehicle, in particular in the field of Vehicle front bumper assembly to be arranged as well as a suitably equipped motor vehicle. In addition refers the invention relates to a method for controlling a for a Motor vehicle provided bumper assembly.

modern Motor vehicles have various protection device to about one better with a vehicle colliding pedestrian to be able to protect. A main focus of such Protective devices is based on a collision of the motor vehicle with particularly vulnerable parts of the body, such as Head and legs. This turns out to be in clashes pedestrians and motor vehicles of the lower leg and knee area as particularly problematic.

One Motor vehicle, which is usually an ordinary Having bumper, in a collision with a pedestrian usually at knee height on, so the pedestrian as a result of a collision can be overturned. Such fatal accident situations To prevent it, there is an aspiration to be a pedestrian in a clash on the comparatively soft bonnet tilt the vehicle.

So exist in the art about protective devices for Vehicles with a bumper arranged transversely in front of the vehicle front and a lower-lying, forward-projecting pedestrian protection part, which prevents a pedestrian in the event of a collision overturned and then run over by the vehicle becomes.

such Protective parts can be used as a reinforcing element for the lower joint area of a front bumper be formed of the motor vehicle. Such become such reinforcing elements also known as "Lower Bumper Stiffener" (LBS) designated. An LBS usually extends substantially in a horizontal direction and is approximately over the entire width of the front bumper extended.

Furthermore, from the DE 198 02 841 A1 discloses a vehicle bumper assembly having an upper impact catcher with a forwardly facing impact surface and a lower impact catcher with a forwardly oriented buffer. The two baffles are movably arranged so that in an approximately impact-induced force action in the rearward direction, by the upper baffle is moved backwards, the lower baffle is moved accordingly forward in an impact position in which the buffer is in front of the impact surface, so that the Impact surface and the bumper slide the body up and in the reverse direction over the bumper assembly.

For this is provided in particular that the two, the upper and the lower impact absorbers are mechanically coupled together.

It may prove to be disadvantageous that for the forward extension of the lower impact absorber a corresponding opposing impact induced movement of the upper impact absorber must be done. This, the forward movement however, the impact causing the lower baffle may taken alone to repel the pedestrian to lead.

In addition, such a system has due to the only in the event of a crash to be moved impact absorber on a certain inertia and a system inherent time delay, which are likely to affect the performance of such a system well. In addition, one claimed from the DE 198 02 841 A1 known mechanical adjusting device of two impact absorbers a considerable amount of space in the front of the vehicle.

Of the The present invention is based on the object, one with regard to pedestrian protection improved Bumper arrangement available too which are easy to manufacture from a production-rational point of view and is inexpensive to implement and the only minor Has a degree of additional space requirements. Further has the invention to the goal of a bumper assembly to create the least possible extension in Has vehicle longitudinal direction.

The The problem underlying the invention is achieved by means of a bumper arrangement according to claim 1 and with a motor vehicle according to claim 12 solved. Furthermore, the invention comprises a method for Control of a planned for a motor vehicle bumper assembly according to claim 13. Individual advantageous embodiments of the invention are in specified in the dependent claims.

The Inventive bumper assembly is intended for a motor vehicle and includes at least a vehicle longitudinally movably arranged bumper element. In addition, the bumper assembly has a control device on which the bumper element in dependence from the speed of the vehicle optionally to a normal position and transferred to an extended position.

On This way will be a bumper assembly created in particular in the pedestrian protection relevant speed range of a vehicle one for the pedestrian protection optimized configuration. Outside of that speed range, on the other hand, the bumper arrangement of space and / or aerodynamic Reasons to convert them into their basic position.

According to the invention thus provided, the bumper assembly independently dependent on a sensory detectable crash situation but from vehicle speed to a pedestrian protection configuration to convict. In this way, the Response time to adjust the bumper assembly on a crash situation can be completely eliminated, so to speak. The bumper assembly according to the invention can be independent from an already existing or imminent sensory detectable Hazard situation, however, depending on a predetermined and relevant to pedestrian protection Speed interval of the vehicle can be configured.

Of Further may be due to the speed-dependent configuration the bumper assembly according to the invention the required space of the bumper assembly be reduced overall. This concerns in particular the extension the bumper assembly in the vehicle longitudinal direction.

To a first advantageous embodiment of the invention is provided that the at least one bumper element in the vehicle longitudinal direction is formed displaceable.

alternative or in addition to this, it may be provided that the bumper element tiltable or pivotable on the bumper assembly is attached. Preferably, a corresponding tilting or pivot axis substantially parallel to the vehicle's vertical axis, so that the bumper element, for example after in front, the front apron of the vehicle ahead, unfolded can be.

By the speed-dependent forward shifting individual or more bumper elements receives the front bumper assembly a for optimized pedestrian protection and energy absorption behavior. In particular, it is intended that the at least one movably arranged bumper element an optimized for pedestrian protection Has deformation and energy absorption behavior.

To a further advantageous embodiment of the invention is provided that the movably mounted bumper element in its extended position from the panel of the vehicle front, especially the front bumper fascia or the front apron of the motor vehicle protrudes. In its Basic position, the bumper element, however, can flush in a corresponding panel be integrated with the vehicle front, so it for example at a parked motor vehicle, in its basic position, for a viewer from the outside hardly noticeable is.

By the extension of the at least one bumper element in the optimized for pedestrian protection Extension position can be achieved by a specially designed for the pedestrian protection provided deformation zone in front of the actual front apron of the vehicle and thus is moved outside the actual vehicle body. Accordingly, the otherwise for corresponding deformation or energy absorption elements required installation space within the vehicle body otherwise find use.

Besides can by the extendability of bumper elements their energy absorption and deformation behavior can be optimized. Thus, for example, with increasing Ausfahrweg an increasing Energy absorption or deformation capacity of the bumper element be achieved.

Besides can by situational, in particular speed-dependent extension of bumper elements a modified basic design and a modified one Arrangement of the entire bumper assembly, in particular the Be reached bumper.

To A further embodiment of the invention provides that the bumper element below an upper limit speed of the vehicle remains in the extended position and above the Border speed goes into the basic position. Especially is at higher, above the upper limit speed lying vehicle speeds retracting the bumper or the elements in their basic position, for example, taking into account Aerodynamic considerations, provided.

Furthermore, it is provided that the at least one bumper element remains below the lower limit speed of the vehicle in the basic position and only transitions into the extended position when this lower limit speed is exceeded. In that regard, it is provided that the at least one bumper element is transferred both below a lower limit speed and above an upper limit speed in the basic position and remains in this, while it is defined in the defined by upper and lower limit speed limit interval in the off driving position passes.

Upper and lower limit speeds are those for pedestrian protection adapted speed range of motor vehicles. In the jargon, this is also referred to as the critical lower leg speed range, between about 25 to 45 kilometers per hour.

One Retraction of the bumper element below the lower limit speed is used in addition to optical and aesthetic Viewpoints also also that the vehicle front area complies with a predetermined ramp angle range. So can for example, by retracting a designed as LBS bumper element a maneuvering and parking of the motor vehicle, in particular Sufficient ramp angles near curbs the front apron can be achieved.

The Retraction and extension of the at least one bumper element between basic position and extended position can be like a hysteresis-like Function done. Thus, for example, be provided, the bumper element extend when the lower limit speed is exceeded, but only when it falls below the lower limit speed by a predetermined amount of speed, of about 5 or 10 km / h back to the basic position.

The Adjusting the at least one bumper element can according to another preferred embodiment means mechanical, electromechanical, hydraulic or pneumatic actuators and / or return means. So, for example be provided, the bumper element with the help inflatable or inflatable air or liquid container to move, tilt or swivel. In addition to such active control mechanisms can also be spring-loaded or spring-loaded Adjustment mechanisms are used.

From Advantage it designed in particular, if the type of adjustment and the associated adjustment an already energy and / or provide shock absorbing function.

To In a further advantageous aspect of the invention, this is at least a movable bumper element as lower and / or as an upper impact catcher, as a corresponding bumper or formed as a corresponding cross member, the or almost completely across the entire width extend the front vehicle front. In particular, can be provided be, the movable bumper element according to Art one for the lower joint area of the front bumper provided reinforcing element, in particular as LBS train in a pedestrian impact the Leg of the pedestrian below the knee area recorded and so an upward, directed towards the hood unwinding supported by the pedestrian.

Besides can be provided, the movable bumper element as an upper impact catcher, approximately as one with a comparatively easily bumped material provided bumper Train at about the knee level of a pedestrian is arranged and a thick-walled layer energy-absorbing and comparatively easily deformable material.

To The invention may further provide that only one, preferably the lower impact catcher as a movable bumper element is trained. In addition, it is conceivable, both an upper as well a lower impact catcher of a bumper assembly extend as a function of the vehicle speed. The extension movement of two vertically spaced apart bumper elements can be coupled to each other, but also decoupled from each other occur.

To a further advantageous embodiment of the invention may also be provided, the movably configured bumper element not over the entire width of the front vehicle front, but seen in the vehicle transverse direction to dimension significantly smaller. For example, it can be provided that the extension of the bumper element Seen in the vehicle transverse direction in about the transverse extent of a Front headlight of the motor vehicle corresponds.

Especially may be provided, the at least one or the movable bumper elements below or in the area of a headlight, especially in this area an additional shock and energy absorption zone to create the motor vehicle apron is upstream.

According to a further advantageous embodiment, it is further provided to form the bumper element as a deformable energy absorption member. It can be provided in particular that the bumper element changes not only its position but also its geometric dimensions when transferring from its basic position to the extended position. For example, it can be provided that the bumper element has a fillable with a gaseous or a fluid medium flexible container which expands under appropriate filling and so, for example, a in the bumper fascia bedded trim part to the outside, the other bumper cover upstream, displaced or pivoted.

Besides but can also be provided, the bumper element even from a shock and energy absorbing material to manufacture, which without significant change in its geometric dimensions between the basic position and the extended position in dependence the vehicle speed can be moved.

To Another independent aspect relates to the invention a motor vehicle with a previously described bumper assembly.

Besides and regardless of the structural design of the previously described bumper assembly according to the invention also a method for controlling a provided for a motor vehicle Buffer arrangement provided, wherein in one first step determines the speed of the vehicle and hereafter, in a second step, the determined vehicle speed with an upper and / or a lower predetermined limit speed is compared.

In Dependence of this comparison or adjustment can then in a third step, at least one bumper element the bumper assembly in an extended position or either extended or retracted to a home position become.

One Extending to the extended position is preferably carried out when the vehicle speed in the upper and lower limit speed certain speed interval passes. Once the vehicle speed this for pedestrian impact protection relevant speed interval leaves, is provided the at least one bumper element back in to transfer his withdrawn basic position.

embodiments

Further Aims, features and advantageous embodiments of the present invention Invention will be described with reference to embodiments described below explained with reference to the drawings. Make up all described in the text as well as in the figures figuratively reproduced features both alone and as in any meaningful combination with each other the object of the present invention.

It demonstrate:

1 A vehicle front section in cross-section with bumper elements in the basic position,

2 a representation according to 1 with bumper elements in the extended position,

3 a perspective view of a vehicle front with bumper elements in basic position,

4 a representation according to 3 with an extended bumper element designed as a lower impact catcher,

5 a front end of the vehicle with a further bumper element in the basic position,

6 the front of the vehicle according to 5 with the bumper element in extended position,

7 a vehicle front in perspective view with a partially folding bumper element in basic position and

8th the embodiment according to 7 with unfolded bumper element.

In the cross-sectional views according to the 1 and 2 is a bumper assembly 10 for the front area of a motor vehicle 12 exemplified. In front of the sketchy sketched front axle or front wheel 14 the motor vehicle has a forward and downward tapered hood 16 as well as a headlight or a headlight module 18 on.

The headlight 18 upstream is the actual bumper assembly 10 , which in the present example a plurality of vertically spaced apart components, namely an upper impact catcher 22 and a lower impact catcher 20 having. The lower impact catcher 20 , which in particular also serves as LBS, forms together with the forward end portion of the upper impact absorber 22 a comparatively soft energy and shock absorption zone. This configuration, optimized for pedestrian protection, allows the leg of a pedestrian to be wrapped around the upper bumper in the early stages of a collision with the vehicle 22 tilts and rises from the lower bumper 20 away.

In the in 1 shown basic position are the upper and the lower bumper 22 . 20 with its front end portions substantially in a vertical line with the front end of the bumper fascia 30 ,

In the in 2 Dashed shown extended position protrude both the upper bumper 22 ' as well as the lower bumper 20 ' from the panel 30 of the bumper. They form in this way an additional, the front apron of the vehicle 12 upstream deformation zone, which allows optimized for pedestrian protection impact behavior.

The variable, speed-dependent retraction and extension of upper and lower bumpers or LBS allows In addition, to maintain a predetermined ramp angle.

The two in the 1 and 2 movably shown upper and lower bumper 20 . 22 can be moved coupled together, but also decoupled from each other as desired depending on the vehicle speed between basic position and extended position to be moved. For optimal pedestrian protection, it is also advantageous if the lower bumper 20 with the upper bumper 22 in a vertical plane or even slightly opposite the upper bumper 22 protrudes.

In the two perspective representations of 3 and 4 is using the same reference numerals as in the 1 and 2 a speed-dependent extension of only the lower impact absorber 20 or LBS 20 shown. In the embodiment according to 3 is the lower impact catcher 20 in its almost invisible basic position, while in 4 horizontally extended to the front.

In this embodiment, the extendable bumper element extends 20 ' almost over the entire width of the front vehicle body. Its geometric shape corresponds essentially to that of a LBS. In the in 4 shown extended position 4 this results in an approximately unfavorable for parking purposes ramp angle. In that the bumper element 20 ' However, only in a given speed interval occupies the extended position shown, but when parking in his in 3 indicated basic position goes back, resulting in the present bumper arrangement hardly disadvantages in terms of the ramp angle to be achieved.

In 5 is a further embodiment of a movably arranged bumper element 24 shown on a front bumper assembly. This bumper element 24 is below the headlight 18 arranged and this at least slightly upstream. It does not extend over the entire width of the vehicle body. It has an extension in the vehicle transverse direction, which is less than the transverse extent of the headlight module 18 is.

The arrangement of an extendable bumper element 24 , in the area or below the headlight module 18 is advantageous insofar as that in this way a required for the purposes of pedestrian protection deformation zone of the bumper fascia 30 can be stored upstream, as in the extended position according to 6 becomes recognizable. Such a forward displacement of a deformation region of a bumper on the other hand, allows the fairing 30 and the bumper underneath, or the bumper at least in the area of the headlight module 18 accordingly thin-walled and thus space-saving design.

The entire vehicle front can thus be made correspondingly shorter, since a deformation and energy absorption layer provided for pedestrian protection purposes is no longer necessarily under the bumper fascia 30 and must be accommodated in front of a headlight housing.

The embodiment according to the 5 and 6 sees a largely linear, extending in the vehicle longitudinal direction moving the bumper element 24 , respectively. 24 ' in front.

In the 7 and 8th which one the 3 to 6 show comparable view of a vehicle front end, is a further embodiment of a pivotally mounted bumper element 26 , in 7 in basic position and in 8th in unfolded position 26 ' , shown. The pivot axis 28 to which the in 8th in its extended position shown bumper element 26 ' is shown, runs substantially parallel to the vehicle's vertical axis.

The pivoting movement of the bumper element 26 as well as the displacement movement of in 5 and 6 shown bumper element 24 and the basis of the 3 and 4 described lower impact absorber 20 can be done in a variety of ways, such as under spring action, with purely mechanical, preferably electromechanical adjusting devices, such as an electric motor. It is also conceivable, by means of inflatable or fillable containers under construction of a gas or fluid pressure, the various bumper elements 20 . 22 . 24 . 26 to transfer to their extended position.

A opposite adjustment for transfer the bumper elements in their normal position can with the same resources, but also with the help of supplementary, take place about spring-loaded return means.

The in the 1 and 2 . 3 and 4 . 5 and 6 such as 7 and 8th illustrated different embodiments of the invention can, depending on the requirements profile and driving tool type can be combined with one another as required and, if necessary, also be coupled with each other.

10

bumper assembly

12

motor vehicle

14

wheel

16

Engine Hood

18

headlights

20

lower impact catcher

22

Oberer impact catcher

24

bumper member

26

bumper member

28

swivel axis

30

paneling

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

• - DE 19802841 A1 [0006, 0009]

Claims (13)

Bumper arrangement for a motor vehicle ( 12 ) with at least one in the vehicle longitudinally movably arranged bumper element ( 20 . 22 ; 24 ; 26 ) and with a control device which the bumper element ( 20 . 22 ; 24 ; 26 ) depending on the speed of the vehicle ( 12 ) optionally converted into a basic position and in an extended position. Bumper assembly according to claim 1, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) Is designed to be displaceable in the vehicle longitudinal direction. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) about an axis extending substantially parallel to the vehicle vertical axis ( 28 ) is mounted tilting or pivoting. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) in its extended position from the fairing ( 30 ) of the vehicle front protrudes. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 24 ; 26 ) in its basic position flush in a panel ( 30 ) of the vehicle front is integrated. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) below an upper limit speed of the vehicle ( 12 ) remains in the extended position and goes above the limit speed in the basic position. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) below a lower limit speed of the vehicle ( 12 ) remains in the home position and goes above the lower limit speed in the extended position. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) is movable by means of mechanical, electro-mechanical, hydraulic or pneumatic actuating means and / or return means between basic position and extended position. Bumper arrangement according to one of the preceding claims, wherein the movable bumper element ( 20 . 22 ) is formed as a lower and / or upper impact catcher, which extends almost completely over the entire width of the front vehicle front. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) below a headlight ( 18 ) is arranged. Bumper arrangement according to one of the preceding claims, wherein the bumper element ( 20 . 22 ; 24 ; 26 ) is formed as a deformable energy absorbing member. Motor vehicle with a bumper assembly according to one of the preceding claims. Method for controlling a bumper arrangement intended for a motor vehicle ( 10 ) according to one of the preceding claims 1 to 11, comprising the following steps: - determining the speed of the vehicle ( 12 ), - comparing the determined vehicle speed with an upper and / or lower limit speed, - extending at least one bumper element ( 20 . 22 ; 24 ; 26 ) in an extended position or retracting the at least one bumper element ( 20 . 22 ; 24 ; 26 ) in a basic position as a function of the determined speed and the predetermined limit speed.