Front crossmember for motor vehicle underbody, underbody and vehicle including such a crossmember.

Abstract

This front crossmember (22) for the vehicle (2) underbody (6) comprises a rear portion (44) forming a beam (46) intended to be in contact with a first side skirt of the vehicle (2) and with a second side skirt of the vehicle (2), a front portion (40) comprising a front piece (42) having a front face (62) intended to be in contact with at least one front side member (14) of the vehicle (2), the front crossmember (22) comprising a first connecting portion (64) extending from a lower end of a front face (50) of the beam (46), the front portion (40) of the crossmember (22) comprising a second connecting portion (66) extending from a lower end of the front piece (42) and connecting to the first connecting portion (64), the beam (46) comprising a recess extending from a lower face (60) of the beam (46) to a face rear (58) of the beam (46). Figure for the abbreviation: Fig 5

Description

Title of the invention: Front cross member for the underbody of a motor vehicle, underbody and vehicle comprising such a cross member. Technical field

[0001] The technical field of the invention is motor vehicles, in particular the underbodies of electric motor vehicles.

[0002] In particular, the present invention relates to a front crossmember for a motor vehicle underbody, a underbody comprising such a crossmember and a motor vehicle comprising such a underbody. Previous techniques

[0003] An electric motor vehicle known from the prior art comprises energy modules, an aluminum housing forming a sealed enclosure and a base.

[0004] The underbody comprises a floor, longitudinal beams, front side members and rear side members.

[0005] The longitudinal beams are each attached at their first end to a front side member of the vehicle and at their second end to a rear side member of the vehicle. The floor extends transversely between the longitudinal beams and extends longitudinally between the front side members and the rear side members.

[0006] The housing comprises a top plate and a reinforced bottom plate opposite the top plate, the housing being fixed to the floor such that the top plate faces the floor.

[0007] The energy modules are arranged in the housing so as to rest on the reinforced bottom plate, the energy modules weighing, for example, more than 400 kilograms.

[0008] Such a vehicle structure comprising a housing provided with a reinforced lower plate is of high mass.

[0009] In addition, such a housing limits the useful volume for storing energy modules. It is therefore useful to rethink the architecture of the underbody of motor vehicles. Statement of the invention

[0010] The present invention aims to propose a motor vehicle underbody structure making it possible to increase the useful volume for storing batteries of a vehicle, to simplify the creation of sealing between the vehicle batteries and the passenger compartment of the vehicle, and to simplify the installation of a vehicle floor.

[0011] The present invention relates to a front cross member for the underbody of a motor vehicle, the cross member comprising a rear part forming a beam intended to be in contact on the one hand with a first side skirt of the vehicle and on the other hand with a second side skirt of the vehicle, a front part comprising a front part provided with a rear face opposite a front face of the beam and a front face intended to be in contact with at least one front side member of the vehicle, the front cross member comprising a first connecting portion extending from a lower end of the front face of the beam, the front part of the cross member comprising a second connecting portion extending from a lower end of the front part and connecting to the first connecting portion, the beam comprising a recess extending from a lower face of the beam to a rear face of the beam.

[0012] The first and second connecting portions allow the movement of the front part of the crossmember relative to the rear part of the crossmember and therefore the deformation of the front crossmember in the event of an impact, in particular a front impact, of a motor vehicle equipped with the front crossmember and protect the rear of the vehicle by absorbing the impact.

[0013] The recess in the beam makes it possible to reduce the weight of the front cross member and to increase the useful volume for storing the vehicle's batteries.

[0014] Advantageously, the first connection portion covers the second connection portion on a covering surface so as to locally form a double thickness of material.

[0015] The first connecting portion may form at least one step between the covering surface and the lower end of the front face of the beam.

[0016] In one embodiment, the front piece is comprised of a first front piece configured to secure a first front spar and a second front piece configured to secure a second front spar.

[0017] Optionally, the front and rear parts are two separate pieces.

[0018] Alternatively, the front part and the rear part form a single piece.

[0019] The front portion of the crossmember may include an upper rim extending to the less partly opposite the rear part from an upper end of the front piece.

[0020] The front portion of the crossmember may include a first lateral flange extending at least partially toward the rear portion from a first lateral end of the front piece.

[0021] The front portion of the crossmember may include a second lateral flange extending at least partially toward the rear portion from a second lateral end of the front piece.

[0022] The present invention also relates to a motor vehicle comprising a front cross member as defined above.

[0023] Advantageously, the vehicle comprises first and second side flaps as well as first and second front side members, the hollow beam being in contact on the one hand with the first side skirt and on the other hand with the second side skirt, the front face of the front part being in contact with the first and second front side members.

[0024] Optionally, the motor vehicle comprises at least one battery, a floor partially inserted into the recess, and a member for attaching the battery to the floor, the attachment member being configured to suspend the battery.

[0025] Optionally, the vehicle comprises a rear cross member connecting the first and second side skirts, as well as a lower closing plate fixed to a lower periphery of the vehicle, in particular formed from a lower surface of the front cross member, a lower surface of the first side skirt, a lower surface of the rear cross member and a lower surface of the second side skirt, a clearance remaining between the battery and the lower closing plate. Brief description of the drawings

[0026] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example and made with reference to the appended drawings in which:

[0027] [Fig-1] schematically illustrates a motor vehicle according to the invention;

[0028] [Fig.2] schematically illustrates a top view of a central part of a base according to the invention;

[0029] [Fig.3] schematically illustrates a cross-section of the central part of the base of [Fig.2];

[0030] [Fig.4] schematically illustrates a “side” view of a front cross member according to the invention;

[0031] [Fig.5] schematically illustrates a “bottom” view of the front crossmember of [Fig.4]; and

[0032] [Fig.6] schematically illustrates an upper floor partially inserted into the recess of the front cross member of [Fig.4]. Detailed description

[0033] [Fig. 1] schematically represents a motor vehicle 2, in particular an electric motor vehicle comprising a plurality of batteries 4, for example in the form of parallelepiped and / or flexible and / or prismatic and / or cylindrical energy cells.

[0034] In the remainder of the description, the terms “longitudinal”, “transverse”, “vertical”, “front”, “rear”, “left”, “right”, “upper”, “lower”, “under” and “on” are understood in relation to the usual orthogonal reference frame for motor vehicles, shown in [Fig.l], and comprising:

[0035] - a longitudinal axis X, horizontal and directed from the front to the rear of the vehicle 2;

[0036] - a transverse axis Y, horizontal, perpendicular to the X axis and directed from left to the right of vehicle 2 moving forward;

[0037] - a Z axis, orthogonal to the X and Y axes, vertical and directed from bottom to top.

[0038] The vehicle 2 comprises a base 6 provided with an upper floor 8, a central frame 10 and a lower closing plate 12. The base 6 also comprises front side members 14 and rear side members 16.

[0039] The upper floor 8 faces the roof 18 of the vehicle 2 and forms a surface delimiting the passenger compartment 20 of the vehicle 2.

[0040] [Fig.2] schematically illustrates a top view of the central part of the base 6.

[0041] The central frame 10 comprises a front cross member 22 on which the front side members 14 are fixed and a rear cross member 24 on which the rear side members 16 are fixed.

[0042] The central frame 10 comprises a first lateral sill 26 and a second lateral sill 28 connected to the front and rear cross members 22, 24 of the central frame 10. Each lateral sill 26, 28 forms a lateral part of the vehicle 2, in particular a lateral part located longitudinally between the wheels of the vehicle 2 and vertically under the doors of the vehicle 2. The lateral sills 26, 28 are also called rocker panels or lower flaps.

[0043] The vehicle 2 comprises a plurality of central crosspieces 30 fixed to the upper floor 8. The central crosspieces 30 are, for example, welded to the upper floor 8, the absence of a fixing hole in the upper floor 8 making it possible to guarantee the sealing, in particular sound and / or thermal, of the passenger compartment 20 at the level of the upper floor 8.

[0044] The central crosspieces 30 are each in contact on either side in the transverse direction of the vehicle 2 with a lateral flap 26, 28.

[0045] [Fig.3] schematically illustrates a cross-section of the base 6 of [Fig.2],

[0046] Advantageously, the upper floor 8 extends vertically from the central crossmembers 30 of the vehicle 2 to a lower periphery of the central frame 10 so that a periphery of the upper floor 8 is fixed, in particular screwed or welded, to a lower periphery of the central frame 10.

[0047] The lower periphery of the central frame 10 is notably formed of a lower surface of the front cross member 22, a lower surface of the first lateral flap 26, a lower surface of the rear cross member 24 and a lower surface of the second lateral flap 28.

[0048] Advantageously, the lower plate 12 is fixed to the lower periphery of the frame. central 10 so that the perimeter of the upper floor 8 is vertically clamped between the central frame 10 and the lower plate 12.

[0049] The upper floor 8 and the lower plate 12 jointly delimit inside the central frame 10 a storage space 32 accommodating the batteries 4 of the vehicle 2.

[0050] The base 6 comprises a plurality of fixing members 34 housed in the storage space 32. Each fixing member 34 is fixed to the upper floor 8, in particular welded to the upper floor 8.

[0051] Each fixing member 34 is configured to suspend at least one battery 4 from the vehicle 2. By “suspending at least one battery from the vehicle” is meant that the battery 4 is supported by the fixing member 34 so that the battery 4 is suspended from the fixing member 34.

[0052] For example, each fixing member 34 comprises a fixing beam extending in the storage space 32, in particular longitudinally. The fixing beam comprises at least one hole formed in a slice of the fixing beam, the battery 4 comprising at least one fixing lug cooperating with the hole to suspend the battery 4 from the fixing beam.

[0053] Advantageously, a vertical clearance 36 remains between each battery 4 housed in the storage space 32 and the upper floor 8 in order to electrically isolate the battery 4 from the upper floor 8.

[0054] Preferably, each fixing member 34 comprises an electrically insulating material in order to electrically insulate the batteries 4 from the upper floor 8.

[0055] Optionally, the base 6 comprises an insulating foam (not shown), in particular for thermal protection, surrounding the battery 4 in the storage space 32.

[0056] Preferably, the thickness of the lower closing plate 12 is less than two millimeters. Since the lower plate 12 does not support the weight of the batteries 4, the thickness of the lower plate 12 is reduced, in particular in order to reduce the mass of the underbody 6 of the vehicle 2.

[0057] The lower plate 12 provides protection for the battery 4, particularly against road debris. Advantageously, a vertical gap 38 remains between each battery 4 fixed to the upper floor 8 by means of a fixing member 34 and the lower plate 12.

[0058] Figures 4 and 5 schematically illustrate a view from the left side of the vehicle 2 and from below the front cross member 22.

[0059] The front crossmember 22 comprises a front part 40 intended to be oriented towards the front of a car and provided with a front part 42. The front part 42 is intended to extend laterally at least partly between the first lateral flap 26 and the second side flap 28, the front piece 42 being able to extend partly beyond an inner lateral face of the first side flap 26 and / or an inner lateral face of the second side flap 28 towards the outside of the vehicle 2, as well as longitudinally from a front end of the first and second side flaps 26, 28 towards the front of the vehicle 2, the front piece 42 being able to extend partly beyond a front face of the first side flap 26 and / or beyond a front face of the second side flap 28 towards the inside of the vehicle 2.

[0060] The front cross member 22 comprises a rear part 44 forming a beam 46 intended to be in contact laterally on the one hand with the first lateral skirt 26 of the vehicle 2, in particular with the inner lateral face of the first lateral skirt 26, and on the other hand with the second lateral skirt 28 of the vehicle 2, in particular with the inner lateral face of the second lateral skirt 28.

[0061] The beam 46 of the front cross member 22 is provided with an upper face 48 intended to be oriented towards the roof 18 of the vehicle 2, a front face 50 opposite a rear face 52 of the front part 42, a first lateral face 54 intended to be oriented towards the first lateral skirt 26, a second lateral face 56 intended to be oriented towards the second lateral skirt 28, and rear 58 and lower 60 faces.

[0062] The front part 42 of the front part 40 comprises a front face 62 intended to be in contact with the front side members 14 of the vehicle 2.

[0063] The front crossmember 22 comprises a first connecting portion 64 extending longitudinally from the lower end of the front face 50 of the beam 46 of the rear part 44 towards the front part 40 of the front crossmember 22. Preferably, the lateral ends of the first covering portion are intended to overlap an edge of the lateral flaps 26, 28.

[0064] The front portion 40 of the front crossmember 22 comprises a second connecting portion 66 extending from the lower end of the front piece 42 towards the rear portion 44 of the front crossmember 22 and connecting to the first connecting portion 64.

[0065] In the example shown, the first connecting portion 64 covers the second connecting portion 66 on a covering surface 68 so as to locally form a double thickness of material, the first and second connecting portions 64, 66 being two separate parts. Alternatively, the second connecting portion 66 covers the first connecting portion 64 on the covering surface 68.

[0066] In another variant, the front cross member 22 is in one piece, the front part 42, the beam 46, the first connecting portion 64 and the second connecting portion 66 forming a single piece.

[0067] In the example shown, the first connecting portion 64 extends the face front 50 of the beam 46 in the plane of the front face 50 of the beam 46, then is folded several times in order to form at least one step 69. The step 69 makes it possible to correct a difference in altitude along the vertical axis Z between the lower end of the front face 50 of the beam 46 and the lower end of the front part 42, the lower end of the front part 42 being here at an altitude lower than the altitude of the lower end of the front face 50 of the beam 46. The step 69 also makes it possible to give a preferred direction of deformation to the front cross member 22 in the event of an impact, in particular a front impact, of the vehicle 2.

[0068] In the example shown, the front piece 42 of the front part 40 is made up of a first front piece 70 and a second front piece 72 of a similar nature to the first front piece 70. The second connecting portion 66 is also made up of a first part extending the lower end of the first front piece 70 and a second part extending the lower end of the second front piece 72.

[0069] The first front piece 70 extends transversely from the first lateral flap 26 to the middle of the front part 40 of the front crossmember 22, the second front piece 72 extending transversely from the second lateral flap 28 to the middle of the front part 40 of the front crossmember 22. In the example shown, the front part 40 of the front crossmember 22 comprises a central rim 74 extending from the end of the first front piece 70 oriented towards the second front piece 72 and partially covering the end of the second front piece 72 oriented towards the first front piece 70 so as to locally form a double thickness of material facilitating in particular the sealed assembly of the first and second front pieces 70, 72. As a variant, the central rim 74 extends from the end of the second front piece 72 and partially covers the end of the second front piece 72.

[0070] The first front part 70 of the front part 40 is adapted for fixing the first front side member 14, intended to be arranged on the right side of the vehicle 2. The first front part 70 allows, for example, the embedding of the first front side member 14 coming into contact with the front face of the first front part 70.

[0071] Advantageously, the first part of the second connecting portion 66 is configured for embedding the first front spar 14. For example, a hole 76 for fixing the first front spar 14 is formed in the covering surface 68 through the first part of the second connecting portion 66 and the first connecting portion 64, the double thickness of material at the covering surface 68 increasing the mechanical strength of the front cross member 22 for fixing the first front spar 14.

[0072] The second front piece 72 of the front part 40 is also adapted for the fixing of the second front side member 14, intended to be arranged on the left side of the vehicle 2. The second front part 72 allows, for example, the embedding of the second front side member 14 coming into contact with the front face of the second front part 72.

[0073] Advantageously, the second part of the second connecting portion 66 is configured for embedding the second front spar 14. For example, a hole 76 for fixing the second front spar 14 is formed in the covering surface 68 through the second part of the second connecting portion 66 and the first connecting portion 64, the double thickness of material at the covering surface 68 increasing the mechanical strength of the front cross member 22 for fixing the second front spar 14.

[0074] The front part 42 comprising the first front part 70 and the second front part 72 simplifies the assembly of the underbody 6 of the vehicle 2. For example, we start by assembling the first front side member 14 with the first front part 70, then we assemble the second front side member 14 with the second front part 72 and finally we assemble the first front part 70 with the second front part 72.

[0075] The beam 46 of the rear part 44 is here of parallelepiped shape, in particular of the shape of a rectangular parallelepiped, and comprises a recess extending from the lower face 60 of the beam 46 to the rear face 58 of the beam 46. The recess is configured so that the beam 46 matches the surface of a part of the upper floor 8 located on the front side of the vehicle 2.

[0076] In the example shown, the hollowed-out beam 46 is formed of a front panel 78 extending from the front face 50 of the beam 46, in particular a panel with a thickness of between 1 and 1.8 millimeters, of an upper panel 80 extending from the upper face 48 of the beam 46, in particular a panel with a thickness of between 1 and 1.8 millimeters, of a first lateral panel 82 extending from the first lateral face 54 of the beam 46, in particular a panel with a thickness of between 1 and 1.8 millimeters, and of a second lateral panel 84 extending from the second lateral face 56 of the beam 46, in particular a panel with a thickness of between 1 and 1.8 millimeters.

[0077] Optionally, the front portion 40 of the front crossmember 22 comprises an upper rim 86 comprising a first portion extending from the upper end of the first front piece 70 and a second portion extending from the upper end of the second front piece 72. Alternatively, the front portion 40 of the front crossmember 22 comprises a single upper rim 86 extending from the upper end of the front piece 42 formed from a single piece. The upper rim 86 makes it possible in particular to improve the fixing of the front side members 14, the upper rim 86 being intended to come into contact with the front side members 14. The upper edge 86 extends, for example, both longitudinally towards the front of the vehicle 2 and vertically upwards.

[0078] Advantageously, the upper rim 86 comprises vertical extensions 88 at each of its lateral ends forming a wall of a front wheel arch of the vehicle 2.

[0079] Optionally, the front portion 40 of the front crossmember 22 comprises a first lateral edge 90 extending from a first lateral end of the front part 42, located on the right side of the vehicle 2 equipped with the front crossmember 22 and a second lateral edge 92 extending from a second lateral end of the front part 42, located on the left side of the vehicle 2 equipped with the front crossmember 22. The first and second lateral edges 90, 92 extend, for example, both laterally outwardly and longitudinally towards the rear of the vehicle 2.

[0080] [Fig.6] schematically illustrates the upper floor 8 partially inserted into the recess of the beam 46 of the front cross member 22, thus increasing the volume of the storage space 32.

[0081] Furthermore, in the event of an impact, particularly a frontal impact of the vehicle 2, the front cross member 22 absorbs the impact, for example following the deformation of the first and second connecting portions 64, 66, and the rear part 44 of the front cross member 22 distributes the impact over the first and second lateral flaps 26, 28, thus protecting the batteries 4.

Claims

Claims

1. Front cross member (22) for underbody (6) of a motor vehicle (2), the cross member (22) comprising a rear part (44) forming a beam (46) intended to be in contact on the one hand with a first side skirt of the vehicle (2) and on the other hand with a second side skirt of the vehicle (2), a front part (40) comprising a front part (42) provided with a rear face (52) facing a front face (50) of the beam (46) and a front face (62) intended to be in contact with at least one front side member (14) of the vehicle (2), characterized in that it comprises a first connecting portion (64) extending from a lower end of the front face (50) of the beam (46), the front part (40) of the cross member (22) comprising a second connecting portion (66) extending from a lower end of the front part (42) and connecting to the first connecting portion (64),the beam (46) comprising a recess extending from a lower face (60) of the beam (46) to a rear face (58) of the beam (46).,

2. Front crossmember (22) according to claim 1, wherein the first connecting portion (64) covers the second connecting portion (66) on a covering surface (68) so as to locally form a double thickness of material.

3. Front cross member (22) according to claim 2, wherein the first connecting portion (64) forms at least one step (69) between the covering surface (68) and the lower end of the front face (50) of the beam (46).

4. A front crossmember (22) according to any one of claims 1 to 3, wherein the front piece (42) consists of a first front piece (70) configured to secure a first front spar (14) and a second front piece (72) configured to secure a second front spar (14).

5. Front crossmember (22) according to any one of claims 1 to 4, in which the front and rear portions (40, 44) are two separate pieces.

6. Front crossmember (22) according to any one of claims 1 to 3, in which the front portion (40) and the rear portion (44) form a single, integral piece.

7. A front crossmember (22) according to any one of claims 1 to 6, wherein the front portion (40) of the crossmember (22) comprises a flange upper (86) extending at least partially away from the rear portion (44) from an upper end of the front piece (42).

8. A front crossmember (22) according to any one of claims 1 to 7, wherein the front portion (40) of the crossmember (22) comprises a first lateral flange (90) extending at least partly towards the rear portion (44) from a first lateral end of the front piece (42) and / or comprises a second lateral flange (92) extending at least partly towards the rear portion (44) from a second lateral end of the front piece (42).

9. Motor vehicle (2) comprising a front cross member (22) according to any one of claims 1 to 8, first and second lateral skirts (26, 28), and first and second front side members (14), the hollow beam (46) being in contact on the one hand with the first lateral skirt (26) and on the other hand with the second lateral skirt (28), the front face (62) of the front part (42) being in contact with the first and second front side members (14).

10. Motor vehicle (2) according to claim 9, comprising at least one battery (4), a floor (8) partially inserted into the recess, and a fixing member (34) for fixing the battery (4) to the floor (8), the fixing member (34) being configured to suspend the battery (4).

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