Crossmember and shock absorber for a front bumper of a motor vehicle
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-03
- Publication Date
- 2026-03-18
AI Technical Summary
Existing motor vehicle front bumper designs fail to adequately protect detection devices, such as ultrasonic generators, cameras, and radars, from damage during low-speed collisions, which can lead to injury and system failure.
Incorporating a shock absorber with a vertical protrusion extending transversely along the crossmember, which limits the sinking of the bumper skin and reduces the movement of detection devices, thereby minimizing the risk of damage during collisions.
The solution effectively protects detection devices by preventing crushing and maintaining their functionality during frontal impacts, enhancing safety and reducing the risk of injury to passengers and pedestrians.
Smart Images
Figure FR2024050430_14112024_PF_FP_ABST
Abstract
Description
Description Title of the invention: Cross member and front bumper shock absorber for motor vehicle
[0001] The present invention claims priority from French application 2304657 filed on May 11, 2023 (11.05.2023), the content of which (text, drawings and claims) is incorporated herein by reference.
[0002] The invention relates to the low-speed front collision of a motor vehicle. The invention relates more specifically to the protection of a detection device mounted in a front bumper skin of a motor vehicle. The invention relates to an assembly for a front bumper of a motor vehicle. The invention also relates to a motor vehicle.
[0003] To reduce obstacle intrusion during a frontal collision, a motor vehicle has a cross member in front of its structure. The cross member is attached to the front side members and is capable of plastically deforming during a high-speed impact, for example at least 50 km / h. This makes deceleration more gradual, reducing the likelihood of injury to passengers.
[0004] Document FR3121091 A1 presents a motor vehicle equipped with a crossmember of a motor vehicle shock absorption system, the crossmember comprising a front wall having a body and at least one skirt extending projecting from the body, vertically downwards in the normal direction of mounting of the crossmember on the vehicle. The crossmember comprises reinforcements fixed to the skirt. Thus, the reinforcements increase the strength of the skirts and in particular their resistance to bending. The skirts can therefore be narrower and allow cooling of the mechanical components, while ensuring a protective function in the event of an impact.
[0005] Furthermore, a motor vehicle is commonly equipped with a plurality of detection devices intended to analyze the environment. This contributes to the detection of objects or bodies potentially forming obstacles. These detection devices thus contribute to passive safety, and offer driving assistance. Such detection devices generally comprise an ultrasonic generator and ultrasonic sensors, or at least one camera, or a radar, or a lidar. In order to optimize the monitoring of the front environment, it is known to arrange at least one detection device on the front facade, in the bumper. A front bumper skin panel is commonly used as a mounting support for such a detection device.
[0006] To protect pedestrians in the event of an impact, an absorber is positioned inside the bumper skin. Document FR3111597A1 presents a motor vehicle comprising a front bumper assembly. The assembly combines a lower bumper grille, a detection radar, and an impact absorber with a cap. The cap in the middle zone of the impact absorber covers the detection radar. It thus provides protection against water flow.
[0007] The front bumper includes the bumper skin that materializes the bodywork. Its various exterior elements contribute to the perceived quality by respecting fine and constant mechanical clearances. They are likely to deform, then return to position following an impact at low speed; for example during a parking maneuver. However, such an event risks damaging the detection device mounted there. Indeed, the latter is a particularly sensitive electronic component.
[0008] The invention aims to address at least one of the problems or drawbacks encountered in the prior art. In particular, the invention aims to preserve a motor vehicle detection device in the event of a collision. The invention also aims to optimize the safety, mass, cooling, and protection of a motor vehicle detection device in the event of a collision.
[0009] According to a first aspect, the invention provides an assembly for a motor vehicle front bumper, the assembly comprising a crossmember with lateral fixing ends, a central zone intended to extend transversely along a detection device mounted in a motor vehicle bumper skin; a vertical extension extending vertically from the central zone; remarkable in that the assembly further comprises a shock absorber with a transverse body extending transversely along the central zone, and a vertical protrusion extending vertically along the vertical extension of the crossmember from the transverse body.
[0010] The invention adds a vertical protrusion to the shock absorber in order to limit the deflection of the bumper skin in the event of a collision. This reduces the displacement of the detection device which is supported by the bumper skin. Thus, the risk of the latter being damaged is reduced; despite its position exposed to obstacles. According to other configurations, the vertical protrusion can form a shock absorber receiving the detection device in the event of a frontal impact.
[0011] Preferably, the lateral fixing ends of the crossmember comprise longitudinal connections extending towards the rear of the central zone; the vertical protrusion of the shock absorber extending perpendicularly to said longitudinal connections.
[0012] Preferably, the vertical protrusion comprises a vertical plate, and at least one vertical connection extending from the vertical plate to the transverse body.
[0013] Preferably, the at least one vertical connection comprises at least two vertical connections separated by a longitudinal passage.
[0014] Preferably, transversely, the central zone of the crosspiece comprises a center, and is arched forward, the vertical protrusion and the vertical extension being arranged transversely to said center; and / or the transverse body comprises an opening transversely at the level of the vertical protrusion.
[0015] Preferably, the central zone comprises an upper plate and a lower plate each with a vertical thickness; the vertical protrusion comprising a longitudinal thickness greater than each vertical thickness.
[0016] Preferably, the detection device is vertically distant from the central zone and the transverse body.
[0017] Preferably, the detection device is fixed to the panel.
[0018] Preferably, the vertical extension comprises a front plate, a rear plate connected to the front plate.
[0019] Preferably, the rear plate is inclined relative to the front plate.
[0020] Preferably, the transverse body comprises an opening transversely at the level of the vertical protrusion.
[0021] Preferably, the transverse body and the vertical protrusion came from the material.
[0022] Preferably, the panel comprises a solid portion opposite the vertical protrusion.
[0023] According to another aspect, the invention proposes a front bumper for a motor vehicle; the front bumper comprising: a bumper skin with an external face, an internal face; a detection device adapted to detect obstacles facing the motor vehicle, said detection device being fixed to the internal face of the bumper skin; a shock absorber with a transverse body and intended to extend transversely along a cross member of the motor vehicle; remarkable in that the shock absorber further comprises a vertical protrusion extending vertically from the transverse body towards the detection device. Such an arrangement preserves the detection device since its crushing is avoided in the event of a frontal impact.
[0024] According to another aspect, the invention provides a motor vehicle comprising an assembly, remarkable in that the assembly is in accordance with the invention, the motor vehicle comprising a bumper skin with an outer face and an inner face, a detection device fixed to the inner face of the bumper skin.
[0025] Preferably, the vertical protrusion extends vertically under the central zone and the detection device is transversely at the level of the vertical protrusion.
[0026] Preferably, the detection device is vertically spaced from the transverse body and the vertical protrusion; and / or the detection device comprises a radar.
[0027] Preferably, the bumper skin comprises a panel extending vertically at the level of the vertical protrusion, the detection device being fixed to said panel.
[0028] Preferably, the panel comprises a horizontal flange extending longitudinally towards the vertical protrusion, and / or the bumper skin comprises at least one grille adjacent to the panel.
[0029] Preferably, the cross member is an upper cross member, the motor vehicle further comprising a lower cross member arranged under the detection device.
[0030] Preferably, the horizontal flange is vertically at the level of the vertical connection.
[0031] Preferably, the horizontal flange is a fixing flange; for example to the grid.
[0032] Preferably, the longitudinal connections comprise energy absorption means.
[0033] Preferably, the lateral fixing ends comprise fixing plates with longitudinal support surfaces.
[0034] Preferably, the detection device is vertically spaced from the vertical extension and / or the vertical protrusion.
[0035] Preferably, the detection device comprises an electronic sensor.
[0036] The invention also relates to a motor vehicle comprising a bumper front; remarkable in that the front bumper is in accordance with the invention.
[0037] Each feature introduced by the expression “preferably” given in relation to one of the aspects of the invention applies to all other aspects of the invention.
[0038] The invention will be well understood and other aspects and advantages will appear clearly on reading the following description, given with reference to the appended figures and listed below.
[0039] Figure 1 is a front view of a motor vehicle according to the invention.
[0040] Figure 2 shows a motor vehicle crossmember according to the invention.
[0041] Figure 3 shows an assembly for a front bumper of a motor vehicle according to the invention.
[0042] Figure 4 is a section of a front facade of a motor vehicle according to the invention, facing an obstacle.
[0043] In the following description, the term "comprise" is synonymous with "include" and is not limiting in that it allows the presence of other elements in the motor vehicle or in the assembly to which it relates. It is understood that the term "comprise" includes the terms "consist of". The terms "external" and "internal" will refer respectively to that which is oriented towards the exterior of the vehicle and towards the interior of the vehicle.
[0044] In this description, the term "longitudinal", the term "longitudinally", the term "transverse", and the term "transversely" are used according to the reference system of the vehicle, in the mounting configuration. The term "longitudinal" corresponds to the main direction of movement of the vehicle. The term "transverse" corresponds to a direction perpendicular to the main direction of movement of the vehicle. The term "front" refers to the main direction of movement of the vehicle. The term "rear" designates the opposite of the front of the vehicle.
[0045] The X axis represents the longitudinal direction, the Y axis represents the transverse direction, and the Z axis represents the vertical direction of the motor vehicle. These three axes define a direct trihedron whose orientation is preserved throughout the figures.
[0046] In this description, the technical characteristics are defined in the assembly configuration of the assembly, unless explicitly stated otherwise.
[0047] Throughout the description, the different figures use the same reference signs to designate identical or similar entities.
[0048] Figure 1 represents a motor vehicle 10 according to the invention. The motor vehicle 10 comprises energy storage means and at least one motor (not shown) adapted to drive said motor vehicle 10.
[0049] The motor vehicle 10 comprises a structure 12. The structure 12 forms an outer body, or even a main frame of the motor vehicle. The structure 12 delimits different compartments of the motor vehicle 10, including the front compartment which is optionally an engine compartment. The structure 12 may be formed from an assembly of stamped sheets welded to each other.
[0050] The structure 12 connects different parts of the motor vehicle 10 including the openings. The structure 12 forms a mounting support for the powertrain, the systems suspension, steering system, braking systems. At the front, the structure includes 14 front side members. The 14 front side members extend to the front compartment.
[0051] The motor vehicle 10 further comprises a bumper assembly 16, preferably a front bumper assembly 16 18. The assembly 16 may be a front fascia assembly. The assembly 16, in particular each of the front bumper entities 18, is adapted to withstand impacts, at speeds up to 10 km / h, preferably up to 15 km / s, without there being any need to replace specific parts of the motor vehicle, and in particular all or part of the bumper skin elements 20. The front bumper assembly 16 18 is also designed to limit the extent of injuries in the event of a pedestrian impact.
[0052] The bumper skin 20 extends to the hood and to the side wings (not shown). The bumper skin 20 delimits air intake openings. These air intake openings are equipped with at least one grille; including an upper grille 22 and a lower grille 24. These grilles form protections against projections.
[0053] A panel 26 is optionally integrated into one of the air inlets; for example in the lower grille 24. The panel 26 is solid. It partially forms the bumper skin 20. The panel may be sealed. A panel is understood to have a smooth and homogeneous extent.
[0054] The assembly 16 comprises a detection device 30. The detection device 30 is arranged behind the panel 26. The detection device 30 allows obstacle detection in front of the motor vehicle 10. Computer means make it possible to detect obstacles and determine their distance. It is coupled to an autonomous driving system and / or to a driving assistance system (not shown). The detection device 30 comprises a radar, such as a front radar. Transversely, it is arranged in a central position in order to optimize the coverage of the environment.
[0055] The assembly 16 also includes a cross member 32. The cross member 32 is a horizontal beam extending laterally. The cross member 32 is arranged between the upper grid 22 and the lower grid 24. The cross member 32 may be a first cross member, or an upper cross member 28. It comprises a metal profile, for example made of steel or aluminum. Other alloys are envisaged in order to increase the capacity to absorb the energy of an impact.
[0056] The cross member 32 comprises lateral ends fixed to the structure 12, more particularly to the front ends of the front side members 14. The fixing can be carried out by means of shock absorption boxes; also designated by the English expression “crash boxes”. In the event of a collision against a fixed obstacle in the environment or another vehicle, the shock absorption boxes deform by dissipating the energy of the impact. They are configured to deform at an impact of a threshold speed, for example of at least 30 km / h. Thus, the assembly 16 is configured to transmit the energy of the impact to the shock absorption boxes for speeds greater than or equal to said threshold speed.
[0057] The assembly 16 further comprises a shock absorber 34. The shock absorber 34 comprises a transverse body. The shock absorber 34 is fixed to the cross member 32. It runs transversely along it over substantially its entire length, and has a complementary shape in order to bear against it in the event of an impact. The shock absorber 34 is made of foam. Alternatively, it comprises a sealed casing. The shock absorber 34 is calibrated to absorb energy in the event of a pedestrian impact; in particular at the level of a leg.
[0058] The assembly 16 for front bumper 18 may also include a second cross member. The second cross member is a lower cross member 36, below the detection device 30 and below the lower grille 24. The lower cross member 36 is below the upper cross member. The lower cross member 36 is configured to absorb energy in the event of a pedestrian impact.
[0059] The motor vehicle may, for example, be a private motor vehicle or a commercial motor vehicle.
[0060] Figure 2 shows a cross member 32 of a front bumper assembly for a motor vehicle. The motor vehicle corresponds to that shown in relation to Figure 1. The shock absorber is not shown for the sake of clarity. A detection device 30 is shown in dotted lines as a reference. This description is detailed in relation to the upper cross member; however, the characteristics also apply to a lower cross member.
[0061] The crossmember 32 comprises lateral attachment ends 38, a central zone 40 extending transversely along the detection device 30. The central zone 40 overlaps the detection device 30. The central zone 40 extends between the lateral attachment ends 38. It is substantially arced forward. The detection device 30 is between the lateral attachment ends 38. The detection device 30 is adapted to detect obstacles facing the motor vehicle. The crossmember 32 further comprises a vertical extension 42 extending vertically from the central zone 40. The vertical extension 42 extends downward. It is oriented towards the detection device 30 in order to contribute to its physical protection.
[0062] The lateral attachment ends 38 of the crossmember 32 comprise longitudinal links 44 extending rearwardly from the central zone 40. They extend opposite the curved shape of the central zone 40. The longitudinal links 44 comprise programmed deformation ribs. These ribs make it possible to control the deformation of the crossmember 32 in the event of a front impact at high speed. The rear ends of the longitudinal links 44 are formed by attachment plates 46. They are perpendicular to the longitudinal direction. They are intended to be attached to the front side members. Therefore, in the event of a collision, the crossmember deforms between the central zone 40 and the attachment plates 46.
[0063] In the middle of the lateral fixing ends 38, the central zone 40 comprises a center 48. It is equidistant from the lateral fixing ends 38. It forms the most forward point of the arcuate shape of the crosspiece 32. The detection device 30 is centered on it.
[0064] The vertical extension 42 includes a front plate 50, a back plate 52 connected to the front plate 50 and inclined relative to the front plate 50. This vertical extension configuration 42 forms a robust stop to protect the detection device 30.
[0065] Figure 3 shows a cross member 32 and a shock absorber 34 of a motor vehicle assembly 16. The motor vehicle corresponds to that shown in relation to one of Figures 1 to 2. The detection device 30 is shown in dotted lines as a reference.
[0066] The shock absorber 34 is horizontal. The shock absorber 34 has a transverse body 54 extending transversely along the central area 40, and a vertical protrusion 56 extending vertically from the transverse body 54. The transverse body 54 and the vertical protrusion 56 are integral. The vertical protrusion 56 of the shock absorber 34 extends perpendicularly to the longitudinal links 44. The vertical protrusion 56 and the vertical extension 42 are transversely at the center (not shown) of the central area 40.
[0067] The vertical protrusion 56 extends; vertically and transversely; along the vertical extension 42 of the crossmember 32. The vertical protrusion 56 covers the vertical extension 42. It masks it. In the event of a frontal collision, the vertical protrusion 56 bears against the vertical extension 42, and crushes against it depending on the speed of the collision. Due to its location, the vertical protrusion 56 is directly above the detection device 30 in order to contribute to its protection. It provides a spacer function.
[0068] The vertical protrusion 56 comprises a vertical plate 58 and at least one vertical connection 60 extending from the vertical plate 58 to the transverse body 54. The vertical plate 58 is a front plate. It is solid. It is perpendicular to the longitudinal direction. The at least one vertical connection 60 comprises at least two vertical connections 60 separated by a longitudinal passage 62. In this case, the vertical plate 58 is attached to the transverse body 54 by three vertical connections 60 which define two longitudinal passages 62. The presence of each longitudinal passage 62 makes it possible to locally reduce the crushing resistance of the vertical protrusion 56, this phenomenon being exploited to protect the detection device 30.
[0069] The transverse body 54 comprises an opening 64 transversely at the level of the vertical protrusion 56. The opening 64 forms a longitudinal passage through the shock absorber 34. It involves a release of material. It compensates for the presence of the vertical protrusion 56, and prevents the formation of a hard point in the event of a pedestrian impact.
[0070] Figure 4 shows in section an assembly 16 for a front bumper 18 of a motor vehicle facing an obstacle 66. The motor vehicle corresponds to that shown in relation to one of Figures 1 to 3. The obstacle 66 is a post having a bump. It is represented via its envelope. According to an alternative, the obstacle 66 is a terminal fixed to the ground. The detection device 30 is also capable of detecting obstacles 66 such as pedestrians or other vehicles.
[0071] The assembly 16 comprising a crosspiece 32 with lateral fixing ends 38, a central zone 40 intended to extend transversely along the detection device 30; a vertical extension 42 extending vertically from the central zone 40 and pointing towards the detection device 30. The vertical extension 42 is hollow in order to lighten it, and to be able to deform in the event of a collision.
[0072] The front face of the cross member 32 is fitted with a shock absorber 34. The shock absorber 34 has a transverse body 54 extending transversely along the central area 40, and a vertical protrusion 56 masking the vertical extension 42 of the crossmember 32. The shock absorber 34 is fixed to the bumper skin 20 to stiffen it. Alternatively, it is fixed to the crossmember 32.
[0073] The central zone 40 comprises an upper plate 68 and / or a lower plate 70; each with a vertical thickness. The upper plate 68 and the lower plate 70 have horizontal portions and inclined portions. The vertical protrusion 56 comprises a longitudinal thickness greater than each vertical thickness of the upper plate 68 and / or the lower plate 70. Thus, the upper plate 68 and / or the lower plate 70 provide a structuring effect by limiting their stiffnesses relative to the vertical protrusion 56. Each thickness may be an average thickness.
[0074] The detection device 30 is vertically spaced from the transverse body 54 and the vertical protrusion 56. The detection device 30 is vertically spaced from the central zone 40 and the transverse body 54. Thus, in the event of a collision, the detection device 30 passes below the shock absorber 34; or more generally below the assembly 16. It avoids destructive crushing.
[0075] The bumper skin 20 has an outer face and an inner face. The detection device 30 is attached to the inner face of the bumper skin 20. The bumper skin 20 comprises a panel 26. The panel 26 is a front panel, in front of the detection device 30 and the vertical protrusion 56. The detection device 30 is attached to the panel 26, on the inner side, in order to be protected by the latter.
[0076] In the event of a frontal collision, the panel 26 comes to bear against the vertical protrusion 56 of the shock absorber 34. This aspect limits the recoil of the detection device 30, and prevents it from being damaged against a rear stop. Its risk of damage is reduced.
[0077] The panel 26 includes at least one horizontal flange 72 extending longitudinally toward the vertical protrusion 56. The horizontal flange 72 is a fixing flange. It extends transversely. In the event of a collision, the horizontal flange 72 pushes into the vertical protrusion 56 until the solid portion of the panel 26 bears against the vertical protrusion 56. This arrangement provides firm support relative to the grid, such as the lower grid 24, which is adjacent to the panel 26.
[0078] The horizontal flange 72 is vertically at the level of the vertical connections 60 and of each longitudinal passage 62. Thus, in the event of a frontal collision, the vertical protrusion 56 presents a controlled resistance to the depression of the horizontal flange 72. Therefore, the recoil of the detection device 30 is controlled in order to preserve it.
[0079] The detection device 30 comprises an electronic sensor. It comprises an electromagnetic wave sensor; possibly coupled to a source of electromagnetic waves. It may comprise optical means.
[0080] The invention includes the combination of all embodiments shown by all figures.
[0081] Figures 2 to 4 are isometric views. They each respect a specific scale.
Claims
Claims
1. Assembly (16) for a front bumper (18) of a motor vehicle (10), the assembly (16) comprising a cross member (32) with lateral fixing ends (38), a central zone (40) intended to extend transversely along a detection device (30) mounted in a bumper skin (20) of a motor vehicle (10); a vertical extension (42) extending vertically from the central zone (40); characterized in that the assembly (16) further comprises a shock absorber (34) with a transverse body (54) extending transversely along the central zone (40), and a vertical protrusion (56) extending vertically along the vertical extension (42) of the cross member (32) from the transverse body (54).
2. Assembly (16) according to claim 1, characterized in that the lateral fixing ends (38) of the crosspiece (32) comprise longitudinal links (44) extending towards the rear of the central zone (40); the vertical protrusion (56) of the shock absorber (34) extending perpendicularly to said longitudinal links (44).
3. Assembly (16) according to one of claims 1 to 2, characterized in that the vertical protrusion (56) comprises a vertical plate (58), and at least one vertical connection (60) extending from the vertical plate (58) to the transverse body (54); preferably the at least one vertical connection (60) comprises at least two vertical connections (60) separated by a longitudinal passage (62).
4. Assembly (16) according to one of claims 1 to 3, characterized in that transversely, the central zone (40) of the crosspiece (32) comprises a center (48), and is arched forward, the vertical protrusion (56) and the vertical extension (42) being arranged transversely to said center (48); and / or the transverse body (54) comprises an opening (64) transversely at the level of the vertical protrusion (56).
5. Assembly (16) according to one of claims 1 to 4, characterized in that the central zone (40) comprises an upper plate (68) and a lower plate (70) each with a vertical thickness; the vertical protrusion (56) comprising a longitudinal thickness greater than each vertical thickness.
6. Motor vehicle (10) comprising an assembly (16), characterized in that the assembly (16) is in accordance with one of claims 1 to 5, the motor vehicle (10) comprising a bumper skin (20) with an outer face and an inner face, a detection device (30) fixed to the inner face of the bumper skin (20); preferably the vertical protrusion (56) extends vertically under the central zone (40) and the detection device (30) is transversely at the level of the vertical protrusion (56).
7. Motor vehicle (10) according to claim 6, characterized in that the detection device (30) is vertically spaced from the transverse body (54) and the vertical protrusion (56); and / or the detection device (30) comprises a radar.
8. Motor vehicle (10) according to one of claims 6 to 7, characterized in that the bumper skin (20) comprises a panel (26) extending vertically at the level of the vertical protrusion (56), the detection device (30) being fixed to said panel (26).
9. A motor vehicle (10) according to claim 8, characterized in that the panel (26) comprises a horizontal flange (72) extending longitudinally towards the vertical protrusion (56), and / or the bumper skin (20) comprises at least one grille adjacent to the panel (26).
10. Motor vehicle (10) according to one of claims 6 to 9, characterized in that the cross member (32) is an upper cross member (28), the motor vehicle (10) further comprising a lower cross member (36) arranged under the detection device (30).