FR3141432A1 - One-piece cross member for automobile vehicle dashboard - Google Patents

Abstract

The invention proposes a one-piece crosspiece (33) for a motor vehicle dashboard which has a structure delimiting a passenger compartment. The one-piece cross member passes through the passenger compartment of the motor vehicle and maintains an external skin forming an internal trim. The one-piece cross member includes: a front face; a back side; two opposite transverse ends (42); a transverse portion connecting the transverse ends; a steering column fixing plate (50) linked to the transverse portion; each transverse end comprises a fixing block (60) with a front portion (62) and a rear portion (64), the front portion comprising a lower extension (66) with an abutment surface (68) abutting against the structure of the motor vehicle. The one-piece crosspiece is made by additive manufacturing. The invention also proposes a motor vehicle with a one-piece crossmember. Figure to be published with the abstract: Figure 3

Description

Single-piece cross member for motor vehicle dashboard

The invention relates to the front collision with low transverse overlap of a motor vehicle. The invention relates more specifically to a reinforced dashboard crossmember of a motor vehicle. The invention also relates to a motor vehicle.

A motor vehicle comprises a dashboard in front of the passenger compartment. A dashboard forms an interior trim piece that runs through the vehicle. In doing so, the dashboard covers and surrounds various components. For example, air vents or screens forming human-machine interfaces are embedded in it. Airbag safety devices are also housed underneath. The elasticity of its skin allows it to absorb slight impacts.

Due to the elongated nature and flexibility of the skin that forms an internal trim, the dashboard has a transversely arranged metal beam. This beam supports the skin and receives the steering column. In order to fulfill all these functions, the dashboard assembly makes the motor vehicle heavier and impacts the driving energy consumption.

Due to the evolution of safety standards, motor vehicles must meet stringent criteria. In the context of front collisions, a motor vehicle must have a minimum absorption in the event of total overlap. In the event of partial overlap of 50%, the motor vehicle complies with certain requirements thanks to reinforcements and dedicated shock absorbers. However, these same reinforcements and absorbers show limited effectiveness when the overlap drops to 25%, and the impact speed is 64 km/h against a fixed obstacle. Such an impact is referred to as a low-overlap collision.

Document FR2975963A1 presents a motor vehicle with a dashboard in front of the passenger compartment and at the base of the windshield. The dashboard is supported by a lower reinforcement piece. It is intended to be secured at the rear face of said dashboard and is made at least partly of textile composite. The reinforcement piece comprises a main support element on which a series of longitudinal ribs and a series of transverse ribs are fixed. The crossmember incorporates two fixing lugs to the dashboard arranged at each of the opposite ends of the crossmember as well as two mounting elements of the crossmember on the body of the vehicle also arranged at each of the opposite ends of the crossmember. Such a crossmember is satisfactory in terms of resistance to the vibration frequency of the steering column and resistance to frontal and lateral impacts of the vehicle. However, there is a need to further improve safety in the event of a low-overlap collision.

The invention aims to address at least one of the problems or drawbacks encountered in the prior art. In particular, the invention aims to improve the safety of a motor vehicle in the event of a low-overlap collision. The invention also aims to optimize the assembly costs, mass and safety of a motor vehicle in the event of a low-overlap collision.

According to a first aspect, the invention proposes a single-piece crossmember for a motor vehicle dashboard which has a structure; the single-piece crossmember being intended to support an outer skin of the dashboard; the single-piece crossmember comprising: two opposite transverse ends; a transverse portion connecting the transverse ends; a steering column fixing plate linked to the transverse portion; remarkable in that at least one or each transverse end comprises a fixing block with a front portion and a rear portion, the front portion comprising a lower extension with a stop surface intended to come into abutment against the structure of the motor vehicle.

Preferably, at least one or each lower extension comprises a horizontal branch extending forward, the stop surface being at the front end of said horizontal branch.

Preferably, at least one or each fixing block comprises two transversely spaced plates connected by internal ribs.

Preferably, at least one or each front portion of the fixing block comprises a lower column extending forward; the lower extension extending longitudinally from said lower column.

Preferably, the single-piece crosspiece comprises at least one arm connecting the transverse portion to one of the two fixing blocks.

Preferably, the arm is inclined relative to the transverse portion and the associated fixing block.

Preferably, at least one or each lower extension comprises means of attachment to the structure of the motor vehicle, said means of attachment passing through the abutment surface.

Preferably, the stop surface is generally horizontal.

Preferably, the single-piece crosspiece comprises a metal profile, and a body made of plastic material overmolded on the metal profile and forming at least one or each lower extension.

Preferably, the transverse portion is a rear transverse portion, the single-piece crosspiece further comprising a front transverse portion connecting the fixing blocks and arranged above the rear transverse portion, said front transverse portion having a front edge intended to hold the outer skin.

Preferably, at least one or each rear portion of the fixing block comprises a rear leg longitudinally opposite the lower extension, said rear leg being intended to hold the outer skin of the dashboard.

It will be understood that the invention proposes a single-block crosspiece with massive fixing ends, which have front stops in the lower part.

Thus, the invention provides a robust fixing of the single-piece crossmember, and ensures front support thanks to the stop against the structure. Thus, the invention limits the rotation of the single-piece crossmember while stiffening the motor vehicle at the front corners of the passenger compartment. Thus, the single-piece crossmember ensures a dual function: support of the skin and safety of the passengers.

Preferably, the abutment surface is vertically and/or longitudinally in abutment against the structure.

Preferably, the single-piece crosspiece has a front face and a rear face opposite the front face, the front part being on the front face.

Preferably, the single-piece crosspiece includes a lower central leg.

Preferably, the single-piece crossmember includes a steering column fixing plate.

Preferably, the single-block crosspiece includes ventilation openings.

Preferably, the stop surface is oriented downwards.

According to another aspect, the invention provides a motor vehicle dashboard assembly, said assembly comprising a single-piece crossmember and an outer skin carried by the single-piece crossmember, remarkable in that the single-piece crossmember conforms to the invention.

According to another aspect, the invention proposes a single-piece crossmember for a motor vehicle dashboard having a structure delimiting a passenger compartment; the single-piece crossmember being intended to traverse the passenger compartment of the motor vehicle transversely; and comprising: a front face; a rear face opposite the front face; two opposite lateral ends, each lateral end comprising a fixing plate with an upper portion and a lower portion; a transverse portion connecting the fixing plates; remarkable in that at least one or each lower portion of the fixing plate comprises a front zone with a stop surface intended to abut against the structure of the motor vehicle; said front zone comprising a front extension extending forward; optionally each fixing plate is integrated into one of the fixing blocks.

According to another aspect, the invention proposes a motor vehicle comprising a structure delimiting a passenger compartment, a single-piece dashboard crossmember, remarkable in that the single-piece crossmember conforms to the invention.

Preferably, the motor vehicle comprises front wheels, at least one or each lower extension extending towards one of said front wheels.

Preferably, the structure comprises a front apron delimiting the passenger compartment, at least one or each abutment surface abutting the front apron; or the structure comprises a front pillar, one of the two abutment surfaces abutting the front pillar.

Preferably, the structure comprises two opposite side walls facing each other; the fixing plates being fixed to said side walls.

According to another aspect, the invention provides a motor vehicle comprising a dashboard assembly, remarkable in that the dashboard assembly is in accordance with the invention.

The invention will be well understood and other aspects and advantages will appear clearly on reading the following description given with reference to the figures annexed and listed below.

There is a side view of a motor vehicle according to the invention.

There is a top view of a portion of a motor vehicle structure according to a first embodiment of the invention.

There is an isometric view of a single-piece motor vehicle crossmember according to a first embodiment of the invention.

There represents a fixing interface at a transverse end of the single-piece crossmember of a motor vehicle according to the first embodiment of the invention.

There is an isometric view of a single-piece motor vehicle crossmember according to a second embodiment of the invention.

In the following description, the term “include” is synonymous with “include” and is not limiting in that it allows for the presence of other elements in the motor vehicle or the one-piece crossmember to which it relates. It is understood that the term “include” includes the terms “consist of”. The terms “external” and “internal” will designate respectively that which is oriented towards the outside of the vehicle and towards the inside of the vehicle.

In this description, the term “longitudinal”, the term “longitudinally”, the term “transverse”, and the term “transversely” are used according to the reference frame 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.

The X axis represents the longitudinal direction, the Y axis represents the transverse direction, and the Z axis represents the vertical direction. These three axes define a trihedron whose orientation is preserved throughout the figures.

In this description, the value ranges include the limits which delimit them.

Throughout the description, the different figures use the same reference signs to designate identical or similar entities.

There 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.

The motor vehicle 10 comprises a structure 12. The structure 12 is adapted to support various parts of the vehicle including the engine or side openings. The structure 12 forms a body. It can be made by assembling stamped sheets welded together. The structure 12 delimits various compartments including the rear trunk, the front engine compartment, and the passenger compartment 14 which is between the latter two. The passenger compartment 14 is intended to accommodate the occupants of the motor vehicle 10, for example at least four occupants.

The structure 12 has at least one front pillar 16, preferably two front pillars 16. The front pillars 16 border the windshield 18, and support the roof. According to one option, the front pillars 16 extend under the windshield 18. They can extend to the level of the front engine compartment of the motor vehicle 10.

The structure 12 further comprises a front apron 20. The front apron 20 delimits the front of the passenger compartment 14, in the lower part; and separates it from the front compartment. The front apron 20 can be formed of a sheet metal, it extends from the floor of the passenger compartment 14. The front apron 20 is arranged under the windshield 18.

The motor vehicle 10 has two side walls 22. The side walls 22 are transversely opposite. They face each other. They may include portions of the structure 12 and side openings.

The motor vehicle 10 also comprises a dashboard assembly 24. The dashboard assembly 24 extends transversely across the entire width of the passenger compartment 14. The dashboard assembly 24 extends from one side wall 22 to the other. The dashboard assembly 24 is arranged at the base of the windshield 18; and overhangs the front apron 20.

The dashboard assembly 24 advantageously comprises a crossmember and a skin (not shown). The skin covers the crossmember. The skin may be a rear envelope, covering the rear and the top of the dashboard assembly 24. The skin may be an external trim. The crossmember may be a single-piece crossmember. The single-piece appearance makes it possible to stiffen the latter.

The motor vehicle 10 comprises a front axle with front wheels 26, and a rear axle with rear wheels 28. According to one option, the dashboard assembly 24 extends vertically at the level of the front wheels 26. Thus, in the event of an impact with a 25% overlap, in particular at a speed of at least 64 km/h, the impacted front wheel 26 is likely to move back relative to the structure 12 and encounter the dashboard assembly 24; or at least its lower portion.

There presents an aerial view of a portion of structure 12 of a motor vehicle. The motor vehicle may correspond to that presented in relation to the . Seats and trim are not shown for clarity.

This portion comprises a part of the passenger compartment 14 and a part of the structure 12 of which the floor 30 and two central side members 32 delimiting the floor 30 are observed. The central side members 32 are lateral side members. The central side members 32 are arranged between the front axle and the rear axle. The passenger compartment 14 has a transverse width L. The transverse width L extends substantially over the entire width of the motor vehicle.

The dashboard assembly 24 has a single-piece crossmember 33 for holding the outer skin (not shown), also called the trim skin. The outer skin partially conceals the front apron 20. The single-piece appearance of the single-piece crossmember 33 allows it to have better resistance in the event of a collision; which increases safety. The single-piece crossmember 33 extends over the transverse width L of the passenger compartment 14. Their widths are substantially equal.

The single-piece crossmember 33 comprises at least one transverse portion 34. The transverse portion 34 horizontally crosses the passenger compartment 14, from one side wall 22 to the other. The transverse portion 34 is generally horizontal. It generally forms a beam. It may be a rear transverse portion 36, also called the first transverse portion. The dashboard assembly 24 further comprises a second transverse portion, also called the front transverse portion 38. The front transverse portion 38 is in front of the rear transverse portion 36. The front transverse portion 38 comprises a front edge 40. The front edge 40 is intended to fit the windshield. The front edge 40 is convex. It is intended to hold the outer skin along the windshield.

The single-piece crossmember 33 comprises two opposite transverse ends 42; including a left end and a right end which are each in contact with the side walls 22 for the purpose of fixing them. The transverse ends 42 are opposite in the transverse direction. Each transverse end 42 can be a lateral end. Furthermore, the single-piece crossmember 33 has a front face 44; and a rear face 46 towards the passenger compartment 14. On the rear face 46 side, and therefore towards the passenger compartment 14, the single-piece crossmember 33 has a steering column fixing plate 50, ventilation openings 52. The upper branches 54 make it possible to maintain the outer skin. The front transverse portion 38 and the rear transverse portion 36 each connect the transverse ends 42.

According to an alternative of the invention, the front transverse portion is an added element.

There shows an isometric view of the single-piece crossmember 33 of a motor vehicle. The motor vehicle may correspond to that presented in relation to one of FIGS. 1 to 2.

The present view shows the steering column mounting plate 50, the air vents 52 and several upper branches 54 for positioning and supporting the outer skin (not shown). The single-piece cross member 33 also has a lower central leg 56. The lower central leg 56 is intended to rest on the structure. Thus, it prevents the single-piece cross member 33 from bending and limits its pivoting about the Y axis.

The steering column mounting plate 50 is in the lower part of the single-piece crossmember 33. Thus, the steering column (not shown) pivots under, and goes around the single-piece crossmember 33 from below. The steering column mounting plate 50 may comprise a plate, possibly slotted for the passage of the steering column. The steering column mounting plate 50 also has fixing holes for fixing a rotating connection of the steering column there, and maintaining the orientation of the axis of rotation of the steering column. Furthermore, the steering column mounting plate 50 is laterally eccentric in order to be on the driver's side.

The steering column mounting plate 50, the upper branches 54 and the lower central leg 56 extend from the rear transverse portion 36. At least one or each of these entities can be used to distinguish the front from the rear of the single-piece crossmember 33; but also the front face 44 from the rear face 46. Openings 58 are provided between the rear transverse portion 36 and the front transverse portion 38. The openings 58 pass vertically through the single-piece crossmember 33.

In the remainder of the description and for the sake of brevity, the single-piece crosspiece 33 will be detailed in relation to one of its transverse ends 42, for example the left. However, the present description applies to each transverse end 42 of the single-piece crosspiece 33.

The transverse end 42 comprises a fixing block 60. The fixing block 60 is intended to fit the structure of the motor vehicle. The fixing block 60 comprises means for fixing to the structure. The fixing block 60 comprises two plates spaced transversely apart and connected by internal ribs. The internal ribs can define a reinforcing lattice between the plates. This embodiment makes it possible to improve the rigidity, while maintaining the stiffness in the event of a collision. Furthermore, the fixing block 60 has a solid appearance, which improves its anchoring to the transverse portion. This limits the pivoting of the fixing block 60 around the Y axis relative to the transverse portion. The rigidity and therefore the safety are reinforced.

The fixing block 60 has a front portion 62 and a rear portion 64. The front portion 62 comprises a lower extension 66 with a stop surface 68 intended to come into abutment against the structure of the motor vehicle. The stop surface 68 is vertically and/or longitudinally in abutment against and/or in contact with the structure. The stop surface 68 is generally horizontal so as to ensure rotational blocking about the Y axis of the single-piece crossmember 33. In addition, this orientation improves the maintenance of the single-piece crossmember 33 on the structure.

The rear portion 64 of the fixing block comprises a rear leg 65 longitudinally opposite the lower extension 66, said rear leg 65 makes it possible to maintain the outer skin (not shown). The positioning of the rear leg 65 at the transverse end 42 makes it possible to maintain the skin from one end to the other.

The lower extension 66 comprises a horizontal branch 70 extending forward, the stop surface 68 being at the front end of said horizontal branch 70. The stop surface 68 being at the front end of the horizontal branch 70. The horizontal branch 70 makes it possible to offset the stop surface 68 and to seek support against the structure. The rotational locking of the single-piece crosspiece 33 is facilitated.

The front portion 62 of the fixing block 60 includes a lower column 72 extending forward and downward. The lower column 72 extends vertically along the rear leg 65. The lower extension 66 extends longitudinally from said lower column 72.

The lower extension 66 comprises means for fixing to the structure of the motor vehicle. These fixing means may comprise a fixing orifice intended to receive a screw cooperating with the structure. Alternatively, they may comprise snap-fastening means intended to cooperate with a complementary orifice in the structure of the motor vehicle. The fixing means pass through the stop surface 68. They are at the front end of the lower extension 66, and of the optional horizontal branch 70.

There has a transverse end 42 of the single-piece crossmember 33 (partially shown), in this case the right side. The motor vehicle may correspond to that presented in relation to one of FIGS. 1 to 3. The following description is in relation to one of the two transverse ends 42, however it applies to both. A portion of the structure 12 of the motor vehicle is shown. A lower section of the front pillar 16 is visible.

The single-piece crosspiece 33 is fixed laterally to the structure 12. In particular, the fixing block 60 is connected to the side wall 22. The latter may have mounting holes to hold the single-piece crosspiece 33 there with fixing pins.

The fixing block 60 bears against the structure 12. In particular, it bears against the front apron 20. At this location, it is capable of limiting the intrusion of the right front wheel in the event of a collision with an overlap of around 25%. The stop surface (not visible) of the fixing block 60 cooperates with the rear surface 74 of the front apron 20. The rear surface 74 faces the passenger compartment. The fixing block 60 comprises two transversely spaced plates connected by internal ribs.

The front transverse portion 38 is optionally elevated relative to the rear transverse portion 36 (partially shown). The rear leg 65 vertically overlaps the fixing block 60.

The single-piece crosspiece 33 comprises at least one arm 76 connecting the fixing block 60 to one of the transverse portions; in this case the rear transverse portion 36. The arm 76 is inclined relative to the transverse portion and to the fixing block 60. The arm 76 forms a connecting arc connecting the transverse portion and the fixing block 60. The single-piece crosspiece 33 has a passage 78 surrounded by the arm 76, the transverse portion and the fixing block 60. The passage 78 extends longitudinally and passes through the single-piece crosspiece 33.

The arm 76 forms a buttress between the fixing block 60 and the rear transverse portion 36. It prevents the fixing block 60 from tilting around the X axis. In addition, in the event of a front collision, the arm 76 helps to limit the pivoting around the Y axis of the fixing block 60 relative to the rear transverse portion 36. The presence of the front transverse portion 38 further limits this risk of pivoting around the Y axis, in addition to limiting the pivoting around the X axis. Thus, the single-piece crosspiece 33 stiffens the structure 12 as a whole.

The invention therefore generates a double reinforcement. The pivots along the X axis and the Y axis are limited by the configuration of the single-block crosspiece 33.

According to one embodiment, the single-piece crosspiece 33 is made of one piece. It may comprise a plastic material, such as polyamide (PA) or polyurethane (PU). The single-piece crosspiece 33 may comprise a composite material. It may be made by molding.

According to yet another alternative, it can be made by three-dimensional printing; also called additive manufacturing. Additive manufacturing allows the single-block sleeper to be made in a succession of superimposed layers.

According to another alternative, the single-piece crosspiece 33 comprises a metal profile and a plastic overmolding on the metal profile. The overmolding forms each fixing block, and in particular each lower extension.

There presents a single-piece crossmember 33 for a motor vehicle according to a second embodiment of the invention. The motor vehicle may generally correspond to that presented in relation to one of the preceding figures. The single-piece crossmember 33 is similar to that of the first embodiment, but is nevertheless distinguished in that the front transverse portion 38 (represented by its ends) is an element added and fixed to the single-piece crossmember 33.

The fixing blocks 60 are connected by the rear transverse portion 36 so as to form a single-piece entity. The fixing blocks 60 include upper fixing wings 80 of the front transverse portion 38. The upper fixing wings 80 extend upwardly. The front transverse portion 38 includes fixing lugs 82 mounted on the upper fixing wings 80. The fixing lugs 82 are at the transverse ends 42. The fixing lugs 82 and the upper fixing wings 80 may be fixed by screws or staples.

Claims (10)

Single-piece crossmember (33) of a dashboard of a motor vehicle (10) which has a structure (12); the single-piece crossmember (33) being intended to support an outer skin of the dashboard; the single-piece crossmember (33) comprising: two opposite transverse ends (42); a transverse portion (34) connecting the transverse ends (42); a steering column fixing plate (50) linked to the transverse portion (34) ; characterized in that at least one or each transverse end (42) comprises a fixing block (60) with a front portion (62) and a rear portion (64), the front portion (62) comprising a lower extension (66) with a stop surface (68) intended to come into abutment against the structure (12) of the motor vehicle (10). Single-piece crosspiece (33) according to claim 1, characterized in that at least one or each lower extension (66) comprises a horizontal branch (70) extending forward, the stop surface (68) being at the front end of said horizontal branch (70), preferably at least one or each fixing block comprises two transversely spaced plates connected by internal ribs. A single-piece cross member (33) according to one of claims 1 to 2, characterized in that at least one or each front portion (62) of the fixing block (60) comprises a lower column (72) extending forward; the lower extension (66) extending longitudinally from said lower column (72). Single-piece crosspiece (33) according to one of claims 1 to 3, characterized in that the single-piece crosspiece (33) comprises at least one arm (76) connecting the transverse portion (34) to one of the two fixing blocks (60), the arm (76) being preferentially inclined relative to the transverse portion (34) and to the associated fixing block (60). Single-piece cross member (33) according to one of claims 1 to 2, characterized in that at least one or each lower extension (66) comprises means of attachment to the structure (12) of the motor vehicle (10), said means of attachment passing through the stop surface (68); the stop surface (68) preferably being generally horizontal. Single-piece crosspiece (33) according to one of claims 1 to 5, characterized in that the single-piece crosspiece (33) comprises a metal profile, and a body made of plastic material overmolded on the metal profile and forming at least one or each lower extension (66). Single-piece crosspiece (33) according to one of claims 1 to 6, characterized in that the transverse portion (34) is a rear transverse portion (36), the single-piece crosspiece (33) further comprising a front transverse portion (38) connecting the fixing blocks (60) and arranged above the rear transverse portion (36), said front transverse portion (38) having a front edge (40) intended to hold the outer skin. Single-piece cross member (33) according to one of claims 1 to 7, characterized in that at least one or each rear portion (64) of fixing block (60) comprises a rear leg (65) longitudinally opposite the lower extension (66), said rear leg (65) being intended to hold the outer skin of the dashboard. Motor vehicle (10) comprising a structure (12) delimiting a passenger compartment (14), a single-piece crossmember (33) of the dashboard, characterized in that the single-piece crossmember (33) conforms to one of claims 1 to 8; preferably the motor vehicle (10) comprises front wheels (26), at least one or each lower extension (66) extending towards one of said front wheels (26). Motor vehicle (10) according to claim 9, characterized in that the structure (12) comprises a front apron (20) delimiting the passenger compartment (14), at least one or each abutment surface (68) abutting the front apron (20); or the structure (12) comprises a front pillar (16), one of the two abutment surfaces (68) abutting the front pillar (16).