Rear bumper structure for motor vehicle

Abstract

The invention relates to a rear bumper structure for a motor vehicle, the bumper structure comprising a support device (11) extending along its own axis of extension (O1), a plurality of prismatic supports (12) projecting from an upper edge of the support device (11), and a plurality of loops (13) projecting from the support device (11) and vertically below the prismatic supports (12), each loop (13) forming a recess (130) delimited by two lateral sides (131) and a distal end side (132) of the support device (11), said recess (130) being located vertically between two directly adjacent prismatic supports (12). Figure to be published with the abstract: Fig. 2

Description

Title of the invention: Rear bumper structure for a motor vehicle

[0001] The technical context of the present invention is that of safety devices for motor vehicles, and in particular that of rear bumpers. More particularly, the invention relates to a rear bumper structure for a motor vehicle.

[0002] In the state of the art, rear bumper supports are known which are fixed to a rear structural panel of the motor vehicle, above a rear bumper beam and which make it possible to support an upper edge of a rear bumper skin in the event of vertical stress exerted downwards on this edge, for example, by luggage placed on this edge before being loaded into the trunk of the vehicle, but also in order to improve the perceived quality by providing vehicle users with a feeling of more rigid support at the level of this upper edge of the bumper skin.

[0003] Furthermore, these rear bumper supports must also be sized to dissipate maximum energy from a repairable impact and transmit minimum stress to the structure, so they generally include compressible elements.

[0004] Document FR3032406 A1 describes a bumper support comprising a main body made of plastic material intended to be fixed by screwing onto the rear structural panel of the vehicle above the rear bumper beam, as well as a plurality of support members projecting at the rear of this main body and intended to be placed just below the upper edge of the bumper skin so as to ensure its support and offer vehicle users a more rigid support feeling.

[0005] Forming a single piece of plastic material with the main body, each of these support members conventionally comprises a supporting panel extending in a vertical plane from the main body to which it is attached, as well as a support plate resting on the upper edge of this supporting panel and forming a support surface for the inner face of the upper edge of the bumper skin.

[0006] These support members are deformable so as to meet passive safety requirements, for example in the event of a repairable impact. For this purpose, the vertical support sections are not oriented longitudinally but have a certain angle of inclination relative to the longitudinal axis of the vehicle. In the event of a collision, the support members then deform by a more pronounced inclination under the effect of the pressure exerted by the bumper skin.

[0007] Among the numerous impact protocols that different models of motor vehicles undergo before being marketed, one of them designated under the name "impact reparability" consists of estimating the cost of repairs on the tested vehicle, when the latter hits at a speed of 16 km / h, a rigid wall inclined at an angle of 10° relative to a plane transverse to the axis of this vehicle with 40% overlap.

[0008] The implementation of such a “repairability shock” thus allows insurance companies to list the different models of motor vehicles tested in different classes according to the cost of repairs, and to adapt their prices accordingly.

[0009] When carrying out this “shock repairability” on motor vehicles equipped with such a bumper support, certain support members may be deformed beyond their elastic limit and are no longer capable of ensuring their function of support and shock absorption, so that it is then necessary to replace the bumper support.

[0010] The object of the present invention is to propose a new rear bumper structure in order to address at least largely the above problems and to further lead to other advantages.

[0011] Another object of the invention is to improve the vertical rigidity of such a rear bumper structure.

[0012] Another aim of the invention is to improve the energy dissipation resulting from a rear impact, and in particular with regard to the repairability impact.

[0013] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a rear bumper structure for a motor vehicle, the bumper structure comprising:

[0014] - a support device extending along a specific extension axis intended to extend mainly according to a cross-section of the motor vehicle;

[0015] - a plurality of prismatic bearing surfaces which project from an edge upper part of the support device and in a direction secant to the proper extension axis

[0016] - a plurality of loops which extend projecting from the support device and the plumb line of the prismatic spans.

[0017] In the context of the present invention, a longitudinal axis, a lateral axis and a vertical axis are defined relative to the motor vehicle on which the bumper structure according to the first aspect of the invention is intended to be mounted. More particularly, the transverse axis is understood as a direction taken between a lateral side of the motor vehicle and an opposite lateral side of said motor vehicle. In other words, the transverse axis is understood in a direction which extends from a passenger side of the motor vehicle to a driver's side of said vehicle at motor vehicle, or vice versa. The adjectives lateral, interior, and exterior refer to such a transverse axis. Furthermore, the longitudinal axis extends as taken along a direction that runs from front to back or from back to front of the motor vehicle. The longitudinal axis is perpendicular to the transverse axis. The adjectives frontal, front, and rear refer to this longitudinal axis. Finally, the vertical axis is understood to be taken along an axis that runs from the wheels of the motor vehicle and toward the roof of said motor vehicle, or vice versa, the vertical axis being simultaneously perpendicular to the transverse axis and the longitudinal axis. The adjectives above and below, or lower and upper refer to this vertical axis.

[0018] Additionally, a proper extension axis is also defined in the frame of reference of the bumper structure, the proper extension axis being defined by the main direction of elongation of the bumper structure, defined in particular by the direction of elongation of the support device and the direction in which the loops and the prismatic bearing surfaces are aligned or substantially aligned. In the context of the integration of the bumper structure into the motor vehicle, the proper extension axis of said bumper structure coincides or substantially coincides with the longitudinal axis.

[0019] In the context of the present invention, the adjective substantially is understood as a condition of equality or identity of a property of one of the structural characteristics described below, or that there is a minimal deviation between said structural characteristic and said corresponding property, the minimal deviation being considered as being less than 10% away from the nominal property to which the adjective "substantially" refers.

[0020] In the context of the present invention, the support device forms a main body serving as a base for the prismatic bearing surfaces and for the loops. Advantageously, the main body forming the support device is provided with means for attachment to a rear structural panel of the motor vehicle to which the rear bumper structure is intended to be connected.

[0021] In the context of the present invention, the prismatic bearing surfaces form support members intended to support an upper edge of a bumper skin associated with the rear bumper. Advantageously, the prismatic bearing surfaces are elastically deformable.

[0022] Optionally, each prismatic bearing surface is attached to the support device, so as to facilitate their replacement in the event of breakage or damage following a rear impact. In this case, the prismatic bearing surfaces are fixed integrally to the support device by any fixing means. Alternatively, each prismatic bearing surface is made in one piece with the support device, so that the prismatic bearing surfaces cannot be detached from the support device without breaking or damaging said support device or at least one of said prismatic bearings. Advantageously, the prismatic bearings are aligned along the proper extension axis of the support device, that is to say relative to the transverse axis.

[0023] In the context of the present invention, the loops also form the support members intended to support the upper edge of a bumper skin associated with the rear bumper. Advantageously, the loops are elastically deformable.

[0024] Optionally, each loop is attached to the support device, so as to facilitate their replacement in the event of breakage or damage following a rear impact. In this case, the loops are fixed integrally to the support device by any fixing means. Alternatively, each loop is made in one piece with the support device, so that the loops cannot be detached from the support device without breaking or damaging said support device or at least one of said loops.

[0025] Advantageously, the loops are aligned along the proper extension axis of the support device, that is to say relative to the transverse axis.

[0026] Thus, the presence of the loops and the clever association of the loops and the prismatic bearing surfaces makes it possible to improve the vertical rigidity of the rear bumper structure in accordance with the first aspect of the invention. Consequently, such a configuration makes it possible to improve the energy dissipation resulting from a rear impact, and in particular with regard to the impact of repairability.

[0027] The bumper structure according to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0028] - each loop forms a closed frame delimited by lateral sides which extend projecting from the support device and an end side extending across the lateral sides, the end side connecting two lateral sides spaced from the support device, the closed frame defining a recess;

[0029] - each loop is located directly above two adjacent prismatic spans, one on the other. More particularly, the loops are located vertically above or below the prismatic spans;

[0030] - the terminal sides of a loop are located directly above two spans taken adjacent to each other, the recess delimited by each closed frame being located between said two adjacent prismatic spans. More particularly, the recess delimited by each closed frame is located between said two adjacent prismatic spans, relative to the proper extension axis;

[0031] - the terminal sides of a loop extend in a plane intersecting the plane in which the corresponding prismatic spans extend.

[0032] - the terminal sides of a loop extend perpendicular to the spans corresponding prismatic. In particular, the prismatic spans extend in a plane mainly formed by the longitudinal axis and the transverse axis, while the terminal sides of the loops extend in a plane mainly formed by the longitudinal axis and the vertical axis;

[0033] - relative to a longitudinal axis perpendicular to the proper extension axis, to the at least a portion of the loops extend beyond the prismatic spans. In other words, a distance between the support device and a free end of the prismatic spans is less than a distance between said support device and the end sides of the loops.

[0034] - more particularly, the bumper structure comprises a first group of loops which extend from the support device at a distance equal or substantially equal to that of the corresponding prismatic spans, and a second group of loops which extend from the support device at a distance greater than that of the corresponding prismatic spans.

[0035] - the first group forms a central group, relative to the proper extension axis, and the second group forms a peripheral group to the central group, the second group having left lateral loops and right lateral loops relative to the central group. In other words, the central group is located in an intermediate position between the first group and the second group, relative to the proper extension axis;

[0036] - each first group and second group of the rear bumper structure advantageously comprises at least two - or even exactly three loops - vertically associated with at least two - or even exactly three loops - pairs of prismatic bearing surfaces. Optionally, the central group of the rear bumper structure advantageously comprises at least one loop vertically associated with at least one pair of prismatic bearing surfaces;

[0037] - the prismatic bearings take the form of legs which extend from the support device. In the context of the present invention, the legs have a thickness taken relative to the vertical axis - much less than their length - taken relative to the longitudinal elongation axis.

[0038] - the terminal sides of the loops form an impact plane inclined relative to the support device. In particular, the terminal sides of the loops are inclined around an axis of rotation substantially oriented along the proper extension axis.

[0039] - an angle of inclination of the terminal sides of the loops relative to the device support is between 5° and 20°. Preferably, the angle of inclination of the terminal sides of the loops relative to the support device is equal to 10°. This confi advantageous configuration makes it possible to make the orientation of the terminal sides of the loops coincide or substantially coincide with an inclination of an impactor used during the rear repairability impact test;

[0040] - each loop and / or each prismatic span is advantageously obtained by molding of a single piece from a thermoplastic polymer such as Polypropylene, optionally filled with natural fibers and / or synthetic fibers in order to improve its mechanical strength. Preferably, the rear bumper structure is obtained by molding of a single piece from a thermoplastic polymer such as Polypropylene, optionally filled with natural fibers and / or synthetic fibers in order to improve its mechanical strength.

[0041] According to a second aspect of the invention, there is provided a motor vehicle comprising a bumper structure in accordance with the first aspect of the invention or according to any of its improvements.

[0042] Various embodiments of the invention are provided, integrating according to all of their possible combinations the different optional characteristics set out here.

[0043] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several exemplary embodiments given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0044] [Fig-1] illustrates an overview of an exemplary embodiment of a structure of rear bumper conforming to the first aspect of the invention;

[0045] [Fig.2] illustrates a three-dimensional detail view of the rear bumper structure illustrated in [Fig.l];

[0046] [Fig.3] illustrates a detailed top view of the rear bumper structure illustrated in [Fig.l].

[0047] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0048] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0049] In the figures, the elements common to several figures retain the same reference.

[0050] In FIGURES 1 to 3, a longitudinal axis X, a lateral axis and a vertical axis Z are defined relative to the motor vehicle on which the bumper structure is intended to be mounted.

[0051] More particularly, the transverse axis Y is understood as a direction taken between a lateral side 131 of the motor vehicle and an opposite lateral side 131 of said motor vehicle. In other words, the transverse axis Y is understood in a direction which extends from a passenger side of the motor vehicle to a driver's side of said motor vehicle, or vice versa. The adjectives lateral, interior and exterior refer to such a transverse axis Y.

[0052] Furthermore, the longitudinal axis X extends as taken along a direction that extends from front to rear or from back to front of the motor vehicle. The longitudinal axis X is perpendicular to the transverse axis Y. The adjectives frontal, front and rear refer to this longitudinal axis X.

[0053] Finally, the vertical axis Z is understood as being taken along an axis which extends from the wheels of the motor vehicle and towards the roof of said motor vehicle, or vice versa, the vertical axis Z being simultaneously perpendicular to the transverse axis Y and to the longitudinal axis X. The adjectives above and below, or lower and upper refer to this vertical axis Z.

[0054] Additionally, a proper extension axis 01 is also defined in the frame of reference of the bumper structure, the proper extension axis 01 being defined by the main direction of elongation of the bumper structure, defined in particular by the direction of elongation of the support device 11 and the direction in which the loops 13 and the prismatic bearing surfaces 12 are aligned or substantially aligned. In the context of the integration of the bumper structure into the motor vehicle, the proper extension axis of said bumper structure coincides or substantially coincides with the longitudinal axis X.

[0055] With reference to FIGURES 1 to 3, the invention relates to a rear bumper structure 1 for a motor vehicle, the bumper structure comprising:

[0056] - a support device 11 extending along the proper extension axis 01 intended to extend mainly along a transverse axis of the motor vehicle;

[0057] - a plurality of prismatic bearing surfaces 12 which extend projecting from an edge upper part of the support device 11 and in a direction secant to the proper extension axis 01;

[0058] - a plurality of loops 13 which extend projecting from the support device 11 and in line with the prismatic spans 12.

[0059] The support device 11 forms a mounting interface on a rear structural panel 10 of the motor vehicle. The support device 11 is fixed by any means to the rear structural panel 10.

[0060] Each prismatic bearing surface 12 extends rectilinearly from the support device 11. In particular, each prismatic bearing surface 12 has a rectangular shape which extends along the longitudinal axis X. Thus, each prismatic bearing surface 12 extends perpendicularly or substantially perpendicularly to the support device 11.

[0061] The bumper structure comprises several prismatic bearing surfaces 12 which are all aligned on the support device 11, relative to the transverse axis Y. The prismatic bearing surfaces 12 are advantageously regularly distributed along the proper extension axis 01. Thus, there is a non-zero distance between two directly adjacent prismatic bearing surfaces 12, relative to the proper extension axis 01.

[0062] Relative to the vertical axis Z, the loops 13 are located directly above the prismatic spans 12. In particular, in the embodiment illustrated in the FIGURES, the loops 13 are located below the prismatic spans 12, relative to the vertical axis Z. Optionally and alternatively, the loops 13 are located above the prismatic spans 12, relative to the vertical axis Z.

[0063] The rear bumper structure 1 comprises a number of loops 13 equal to half the number of prismatic bearing surfaces 12. In fact, each loop 13 is associated with a pair of prismatic bearing surfaces 12s. In the example illustrated in the FIGURES, the rear bumper structure 1 comprises seven loops 13 associated respectively with fourteen prismatic bearing surfaces 12.

[0064] In the example illustrated in the FIGURES, the loops 13 comprise:

[0065] - a first group G1 formed by three loops 13 each associated with a pair of prismatic bearings 12, the first group G1 being located at a first lateral end of the support device 11, relative to the proper extension axis 01;

[0066] - a second group G2 formed by three loops 13 each associated with a pair of prismatic bearing surfaces 12, the second group G2 being located at a second lateral end of the support device 11, opposite the first end, relative to the proper extension axis 01;

[0067] - a central group G3 formed by a loop 13 associated with a pair of spans taken matics 12, the central group G3 being located in an intermediate position between the first group G1 and the second group G2, relative to the proper extension axis 01.

[0068] Each loop 13 forms a closed frame delimited by lateral sides 131 and an end side 132. The lateral sides 131 extend projecting from the support device 11, relative to the longitudinal axis X. The lateral sides 131 extend in a rectilinear manner. Furthermore, the lateral sides 131 each form a sheet which extends in a plane perpendicular to that in which the prismatic bearing surfaces 12 extend. In this case, the lateral sides 131 delimiting the loops 13 extend in a plane formed by the longitudinal axis X and the vertical axis Z, while the bearing surfaces prismatic 12 extend in a plane formed by the longitudinal axis X and the transverse axis Y.

[0069] The terminal ribs of the loops 13 extend across the lateral sides 131, at a distance from the support device 11. The terminal sides 132 connect each lateral side 131 of a loop 13. The terminal sides 132 are rectilinear. The terminal sides 132 extend in a plane inclined relative to a vertical plane. In particular, an angle of inclination of the terminal sides 132 is advantageously greater than 5°, preferably between 5° and 15°, preferably equal to 10°. This advantageous configuration makes it possible to match - that is to say to make parallel or substantially parallel - the plane formed by the terminal sides 132 of the loops 13 and the impactor 2 used in the repairability test of a rear impact, thus improving the score of the motor vehicle.This advantage is achieved through better dissipation of the mechanical energy from the impact in the rear bumper structure 1, thanks to the clever configuration of the loops 13 and the prismatic bearing surfaces 12.

[0070] The lateral sides 131 and the terminal side 132 of a loop 13 together delimit a central recess 130. Thus, the lateral sides 131 and the terminal side 132 of a loop 13 together form a closed box which makes it possible to improve the mechanical response of the rear bumper structure 1. Advantageously, the loops 13 are regularly distributed along the proper extension axis 01. In particular, the distribution of the loops 13 along the proper extension axis 01 is such that each recess 130 is aligned with respect to the pair of associated prismatic bearing surfaces 12, that is to say located directly in line with each other. In other words, for a given pair of prismatic bearing surfaces 12, the recess 130 of the corresponding loop 13 located directly below is located between the two prismatic bearing surfaces 12.

[0071] In summary, the invention relates to a rear bumper structure 1 for a motor vehicle, the bumper structure comprising a support device 11 extending along a specific extension axis 01, a plurality of prismatic bearing surfaces 12 which project from an upper edge of the support device 11, and a plurality of loops 13 which project from the support device 11 and in line with the prismatic bearing surfaces 12, each loop 13 forming a recess 130 delimited by two lateral sides 131 and a distal end side 132 of the support device 11, said recess 130 being located in line between two directly adjacent prismatic bearing surfaces 12.

[0072] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other according to various combinations to the extent that they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

Claims

1. Rear bumper structure (1) for a motor vehicle, the bumper structure comprising: - a support device (11) extending along a specific extension axis (01) intended to extend mainly along a transverse axis of the motor vehicle; - a plurality of prismatic bearing surfaces (12) which extend projecting from an upper edge of the support device (11) and in a direction intersecting the specific extension axis (01); characterized in that the support device (11) comprises a plurality of loops (13) which extend projecting from the support device (11) and in line with the prismatic bearing surfaces (12).

2. Rear bumper structure (1) according to the preceding claim, in which each loop (13) is located directly above two prismatic bearing surfaces (12) adjacent to each other.

3. A rear bumper structure (1) according to any preceding claim, wherein each loop (13) forms a closed frame delimited by lateral sides (131) which extend projecting from the support device (11) and an end side (132) which extends across the lateral sides (131), the end side (132) connecting two lateral sides (131) at a distance from the support device (11), the closed frame delimiting a recess.

4. Rear bumper structure (1) according to the preceding claim, in which the recess (130) delimited by each closed frame is located between the two adjacent prismatic bearing surfaces (12), relative to the proper extension axis (01).

5. Rear bumper structure (1) according to any one of the preceding claims, wherein, relative to a longitudinal axis (X) perpendicular to the proper extension axis (01), at least a portion of the loops (13) extend beyond the prismatic bearing surfaces (12).

6. Rear bumper structure (1) according to any one of the preceding claims taken in combination with claim 3, wherein the end sides (132) of the loops (13) form an impact plane inclined relative to the support device (11).

7. Rear bumper structure (1) according to the preceding claim, wherein an angle of inclination of the end sides (132) of the loops (13) relative to the support device (11) is between 5°

8. and 20°. Motor vehicle comprising a rear bumper structure (1) according to any one of the preceding claims.

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