CROSS BEAM FOR MOTOR VEHICLE UNDERBody STRUCTURE AND VEHICLE INCLUDING SUCH A CROSS BEAM

Abstract

The invention relates to a seat cross member (7) for a motor vehicle underbody structure (1), said cross member (7) having an elongated shape and being configured to be fixed to a floor (3) of an underbody structure (3), said cross member (7) comprising a face (9a), referred to as the first face, having portions (11, 13) situated in distinct planes and a connecting zone (15) linking said portions (11, 13) together, characterized in that said cross member (7) comprises at least one stiffening structure (18) which includes a stamped section (19) arranged at the level of said connecting zone (15). [Fig. 2]

Description

Title of the invention: SEAT CROSS BEAM FOR MOTOR VEHICLE UNDERBody Structure AND VEHICLE COMPRISING SUCH A CROSS BEAM

[0001] The present invention relates to the general field of motor vehicles, and more particularly to a seat crossmember for a motor vehicle underbody structure.

[0002] Indeed, a motor vehicle commonly includes a subframe structure on which various elements are fixed, such as rocker panel members, side members, beams, cross members, etc., the whole thus defining a body structure of the vehicle.

[0003] The underpinning structure of a vehicle includes in particular a floor which defines for example the floor area of ​​a passenger compartment of the vehicle, a floor on which are mounted, among other things, driver and passenger seats.

[0004] Thus, during the manufacture of underbody structures for a motor vehicle, the floors are prepared with one or more seat cross members onto which seats are subsequently fixed (for example, by means of a slide). The seat cross member is generally a beam, for example hollow, fixed between two (lateral) side members of the underbody structure or between a side member of the underbody structure and a transmission tunnel.

[0005] A seat crossmember is thus positioned near the floor of the underbody structure and allows for the proper mounting of the seats. Such a seat crossmember is generally located directly above a structural member of the vehicle, which, for the front seat crossmember of the vehicle, corresponds to a central door pillar.

[0006] In the case of a vehicle without a transmission tunnel, the front seat crossmember of the vehicle means a seat crossmember that extends between the two front side members of the vehicle and supports the driver's and front passenger's seats. In the case of a vehicle with a transmission tunnel, the front seat crossmember means one or the other of the driver's or front passenger's seat crossmembers, each extending between a front side member of the vehicle and the transmission tunnel.

[0007] In the event of a side impact on the vehicle, some of the forces resulting from the impact are transmitted through the vehicle's underbody structure. One particular stress zone is located in the front crossmember of the vehicle. This crossmember is subjected not only to lateral forces resulting from the impact, but also to the load of the central door pillar which each tend to cause a flexion of the front seat cross member.

[0008] Such a bending compromises the transfer of forces in the underbody of the vehicle and does not allow shock management in line with the safety of the vehicle's passengers (and / or compliance with the biomechanical criteria of said passengers).

[0009] It should also be noted that changes in height (or plane) of one of the faces of a seat crossbeam are particularly fragile areas during a lateral impact.

[0010] It is therefore necessary to find a solution which ensures the safety of passengers during an accident, while avoiding an increase in the weight of the vehicle and / or the cost of manufacturing said vehicle.

[0011] The present invention thus proposes to remedy at least one of the aforementioned drawbacks by proposing a new type of seat cross member for the underbody structure of a motor vehicle, said cross member having an elongated shape and being configured to be fixed to a floor of an underbody structure, said cross member comprising a face, said first face, having portions located in distinct planes and a connection zone linking said portions together, characterized in that said cross member includes a stiffening structure which includes at least one stamping arranged at the level of said connection zone.

[0012] The seat crossmember according to the invention is a simple and inexpensive solution for improving the mechanical behavior of a seat crossmember and increasing passenger safety during a collision. Furthermore, the seat crossmember according to the invention does not require the addition of any parts or materials, thus avoiding an increase in manufacturing costs and the weight of the seat crossmembers, and by extension, of the motor vehicle.

[0013] According to one possible feature, said at least one stamped part has a substantially elongated shape and extends substantially along the longitudinal axis of said cross member. Advantageously, the largest extension dimension of the stamped part extends substantially parallel to the longitudinal axis of said cross member, in order to improve the mechanical behavior of the connection area, and therefore of the cross member, during impacts.

[0014] According to another possible feature, the connecting zone has a radius of curvature, said at least one stamping being configured to locally reduce the radius of curvature of said connecting zone. Advantageously, the stamping, which is a local deformation of the material forming the bonding zone, makes it possible to modify the radius of curvature of said zone, in particular by reducing (or even locally eliminating) it, making the bonding zone more rigid, thus improving the mechanical behavior of said cross member during an impact.

[0015] According to another possible feature, said at least one stamping extends beyond the bonding area which has a radius of curvature. The fact that said at least one stamping extends beyond the portion of the connection area having a radius of curvature, for example along the longitudinal axis of said cross member, makes it possible to improve the mechanical behavior of the connection area, and therefore of the cross member.

[0016] According to another possible characteristic, said at least one stamped part has a substantially triangular or trapezoidal shape. Advantageously, a triangular or trapezoidal stamped section allows for better mechanical behavior of the cross member's connection area during an impact.

[0017] According to another possible feature, said cross member has at least three faces extending in distinct planes, the first face and two lateral faces, referred to as the second face and third face, the first face being connected to each of said lateral faces via one of its transverse edges. It should be noted that said support beam is, for example, a hollow metal beam or a metal profile, said beam being intended to be fixed, for example by welding, to a floor of a motor vehicle underbody structure.

[0018] According to another possible feature, said stiffening structure comprises at least two stamped sections spaced apart, one stamped section being provided on each of the lateral edges of the first face. Advantageously, the stiffening structure has two stamped sections arranged at a distance from each other and located on the lateral edges (or lateral extremities) of the first face of said cross member, in order to optimize the mechanical behavior of the connection area, and therefore of the cross member, during an impact.

[0019] It should be noted that the fact that the said at least two stamped parts do not overlap or are not in contact with each other limits the disturbances by interference between the said stamped parts during a shock, and therefore limits a degradation of the mechanical behavior of the said connection zone.

[0020] According to another possible feature, said at least two stamped parts are arranged opposite each other. The said at least two stamped sections are arranged opposite each other (or facing each other), in order to guarantee the most homogeneous mechanical behavior possible of the crossmember regardless of the impact, and in particular the angle of said impact relative to the vehicle's underbody structure.

[0021] According to another possible feature, said seat cross member is configured to extend, in mounted position, between two side members of a subframe structure or between a side member and a transmission tunnel.

[0022] The invention also relates to a motor vehicle underbody structure, characterized in that said underbody structure comprises a seat cross member as defined above.

[0023] The invention also relates to a motor vehicle, characterized in that said vehicle, for example thermal, electric or hybrid, comprises a substructure as defined above.

[0024] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of a particular embodiment of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings, in which: - Fig. 1 illustrates a schematic and perspective top view of a subframe structure according to the invention for a motor vehicle; - [Fig.2] is a schematic, partial and enlarged view of a foundation beam of the substructure of [Fig.1]; - [Fig.3] is another schematic, enlarged, partial and perspective view of the seat crossbeam of [[Fig.2]].

[0025] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other elements in the vehicle, or the structure to which it relates.

[0026] It is understood that the term "include" includes the terms "consist of". Similarly, the terms "lower", "upper", "front", "rear", "longitudinal" and "transverse" shall be understood in relation to the general orientation of the motor vehicle, unless otherwise stated.

[0027] Furthermore, an orthogonal XYZ frame of reference is defined with respect to the vehicle (or a vehicle underbody structure), namely: - an X-axis, defining a longitudinal and horizontal direction of the vehicle, - a Y-axis, defining a transverse and horizontal direction, which together with the X-axis defines a horizontal XY plane, - a Z axis, defining a vertical direction, orthogonal to the horizontal XY plane, the Z axis with the X axis or with the Y axis defining a vertical plane XZ or YZ.

[0028] The term "lower" will denote a greater proximity to the ground than "upper" along the vertical axis. Furthermore, it should be noted that in the various figures, the same reference numerals designate identical or similar elements.

[0029] In this application, it should be noted that "substantially parallel" means a direction deviating by no more than 20°, or even by no more than 10° or 5°, from a parallel direction. It should also be noted that "substantially orthogonal" means a direction deviating by no more than 20°, or even by no more than 10° or 5°, from an angle of 90°.

[0030] Fig. 1 illustrates a schematic and perspective top view of a subframe structure 1 according to the invention intended to be mounted in a motor vehicle, for example a thermal, electric or hybrid vehicle.

[0031] Said subframe structure 1 thus includes a floor 3 which defines for example the floor area of ​​a passenger compartment of the vehicle, and various elements fixed to said floor 3, for example side rails 5 fixed to the side edges of the floor 3. It should be noted that the floor 3 and the side rails 5 are generally metallic, for example made of steel or a steel alloy.

[0032] Furthermore, said floor 3 has two opposing main faces: - a first face 3a, called the internal or upper face, configured to be oriented, in the mounted position, upwards (or towards the vehicle); - a second face (not visible), called the external or lower face, configured to be oriented, in the mounted position, towards the outside (of the vehicle or the substructure) or downwards.

[0033] Said substructure 1 also includes a bearing crossbeam 7 fixed to the floor 3 of the substructure 1, more particularly said bearing crossbeam 7 is advantageously fixed to the first face 3a of the floor 3.

[0034] Said cross member 7 has an elongated shape and extends substantially orthogonally to the longitudinal axis of the vehicle (or X axis), or substantially parallel to the transverse axis of the subframe structure 1 (or of the vehicle, i.e. the Y axis).

[0035] Said cross member 7 thus extends, in mounted position, between the two longitudinal members 5 of the subframe structure 1, or in an unrepresented embodiment of the invention, between a longitudinal member and a transmission tunnel.

[0036] Said cross member 7 is, for example, a hollow metal beam or a metal profile. Said cross member 7 is advantageously made of steel or a steel alloy, for example by stamping, bending, etc. Said cross member 7 is further advantageously fixed by welding to the floor 3 and / or other elements of the substructure 1, for example to the stringers 5.

[0037] Fig.2 and Fig.3, meanwhile, are schematic and perspective views of the seat cross member 7, respectively in the mounted position on the floor 3 and the cross member 7 alone.

[0038] Said crossbeam 7 thus comprises at least three faces 9a, 9b and 9c which extend in distinct planes: - a first face 9a, or upper face, which extends, in the mounted position of the cross member 7, in a substantially horizontal plane and which has portions 11 and 13 located in distinct planes (but planes substantially parallel to each other), that is to say at different heights or altitudes; - two lateral faces 9b and 9c, called second face and third face, which each extend in a substantially vertical plane (planes substantially parallel to each other).

[0039] It will be noted that the different faces 9a, 9b and 9c of the cross member 7 are formed by one or more walls forming said cross member 7.

[0040] The first face 9a of the cross member 7 is thus connected, for example substantially orthogonally, to each of the lateral faces 9b, 9c via one of its transverse edges (or transverse ends). The cross member 7, for example, has a substantially U-shaped cross-section (the open end of the U bearing against the first face 3a of the cross member 3).

[0041] In the mounted position, the first face 9a is thus oriented upwards. Furthermore, said cross member 7 includes a connecting zone 15 allowing said portions 11 and 13 to be connected together.

[0042] Said connecting zone 15 has substantially an angled or curved shape, and therefore has a radius of curvature or a concavity. The radius of curvature of said connecting zone 15 is thus oriented towards the interior of the cross member 7 (i.e. in the direction of the volume delimited by the lateral faces 9b and 9c), or, in the mounted position, downwards.

[0043] Said seat cross member 7 further includes a stiffening structure 18 which includes at least one stamped part 19 arranged at the connection zone 15. It should be noted that in the embodiment described herein, the stiffening structure 18 advantageously includes two stamped parts 19.

[0044] It can also be noted that the term "stamped" refers to the local deformation of the wall forming the connection zone 15 of the first face 9a of the cross member 7.

[0045] Thus, the stamped parts 19 each have substantially an elongated shape, the main (or most important) extension dimension of said stamped parts 19 extending along the longitudinal axis of the cross member 7 (therefore, in the mounted position of the cross member, substantially along the Y axis or substantially orthogonally to the X axis).

[0046] In addition, at least one embossed 19 is provided on each of the lateral edges of the first face 9a, that is to say near the junction between the first face 9a and respectively each of the lateral faces 9b and 9c.

[0047] The two stamped parts 19 are thus arranged at a distance from each other and advantageously opposite each other (or facing each other), there is thus a space in the connection zone 15 without modification or stamping separating the two stamped parts 19 from the stiffening structure 18.

[0048] In addition, each of the stamped parts 19 extends beyond the connection area 15 which has a radius of curvature, either into a part of the connection area 15 which does not have a curvature, or into the portions 11 and 13.

[0049] Furthermore, each of said stamped parts 19 has substantially a triangular shape, such as a right angle, trapezoidal or polygonal shape, of which the The main extension dimension extends along the longitudinal axis of said cross member 7 (i.e. the Y axis in the mounted position of said cross member).

[0050] In addition, each of said stampings 19 is configured to reduce, or even cancel, locally the radius of curvature of said connection zone 15. Thus, the local deformation generated by each of said stampings 19 is carried out in the direction opposite to the radius of curvature, in order to modify locally, here reduce (or even cancel), the radius of curvature of said connection zone 15.

[0051] Each of said stampings 19 is therefore oriented away from the first face 9a and the lateral faces 9b and 9c, that is to say that, in the mounted position, the stampings 19 are oriented upwards.

[0052] It should also be noted that said crossbeam 7 may include several connection zones 15 (and therefore several associated portions 11 and 13), each of said connection zones 15 comprising a stiffening structure 18 as described above.

[0053] In an unrepresented embodiment of the invention, the stiffening structure comprises a single stamping arranged at the connection area of ​​said cross member, said stamping being located between the lateral edges of the first face of said seat cross member, that is to say that the stamping is laterally centered on the first face of the cross member.

Claims

Demands

1. Cross member (7) for underbody structure (1) of motor vehicle, said cross member (7) having an elongated shape and being configured to be fixed to a floor (3) of an underbody structure (3), said cross member (7) comprising a face (9a), referred to as first face, having portions (11, 13) situated in distinct planes and a connecting zone (15) connecting said portions (11, 13) to each other, characterized in that said cross member (7) comprises a stiffening structure (18) which includes at least one stamping (19) arranged at the level of said connecting zone (15).

2. Cross member (7) according to the preceding claim, characterized in that said at least one stamped part (19) has substantially an elongated shape and extends substantially along the longitudinal axis of said cross member (7).

3. Cross member (7) according to any one of the preceding claims, characterized in that the connection zone (15) has a radius of curvature, said at least one stamping (19) being configured to locally reduce the radius of curvature of said connection zone (15).

4. Cross member (7) according to the preceding claim, characterized in that said at least one stamped part (19) extends beyond the bonding area (15) which has a radius of curvature.

5. Cross member (7) according to any one of the preceding claims, characterized in that said at least one stamped part (19) has a substantially triangular or trapezoidal shape.

6. Cross member (7) according to any one of the preceding claims, characterized in that said cross member (7) has at least three faces (9a, 9b, 9c) extending in distinct planes, the first face (9a) and two lateral faces (9a, 9c), referred to as the second face and third face, the first face (9a) being connected to each of said lateral faces (9b, 9c) via one of its transverse edges.

7. Cross member (7) according to the preceding claim, characterized in that said stiffening structure (18) comprises at least two stamped pieces (19) spaced apart from each other, one stamped piece (19) being arranged on each of the lateral edges of the first face (9a).

8. Crossbar (7) according to the preceding claim, characterized in that said at least two stamped pieces (19) are arranged opposite each other.

9. Underbody structure (1) for motor vehicle, characterized in that said underbody structure (1) comprises a seat cross member (7) according to any one of the preceding claims.

10. Motor vehicle, characterized in that said vehicle comprises a subframe structure (1) according to the preceding claim.

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