vehicle with support box for stretcher under hollow floor

Abstract

The invention relates to a hybrid or electric vehicle (1) comprising a structure (1a) having a floor (2), a seat crossmember (4) extending transversely under the floor (2) along a battery compartment (5), and at least one subfloor stretcher (3) extending longitudinally under the floor (2), the subfloor stretcher (3) being hollow and having a constant cross-section. The structure (1a) includes a support box (6) positioned on the seat crossmember (4), the subfloor stretcher (3) extending to the support box (6) so as to have one end (7) opposite the support box (6). (Fig. 1)

Description

Title of the invention: Vehicle with support box for stretcher under hollow floor Technical field of the invention

[0001] The invention relates, in general, to the technical field of electric or hybrid motor vehicles, and more particularly to their structures for the absorption of impact energy in the event of a collision.

[0002] The invention relates more particularly to the resistance of hollow-body underfloor stretchers to frontal impacts. Prior art

[0003] Among the structural elements of the underbody of a vehicle, the stretcher is designed to transmit the most forces in the event of a frontal impact.

[0004] The vehicle structure comprises a floor, a seat crossmember extending transversely under the floor along a battery compartment located under the seat cushions, and generally two frame members, each comprising a portion usually called an underfloor frame member because it is fixed under the vehicle floor. Each underfloor frame member extends longitudinally along and under the floor to the seat crossmember.

[0005] Each underfloor frame is formed from a stamped sheet of metal and is hollow. This hollow body is very close to the ground. This does not pose any problem in internal combustion engine vehicles, but it limits the possibilities for installing underfloor batteries in hybrid or electric vehicles. The batteries must then span the underfloor frames, which limits the number or size of battery modules that can be installed.

[0006] One solution for increasing the size of underfloor batteries is not to span the underfloor supports but to cut them. The load transfer would then be handled by the battery casing or by protective frames designed and arranged for this purpose.

[0007] However, cutting the underfloor stretchers presents the risk of degrading the integrity of the underbody during high-speed frontal impacts.

[0008] In addition, the underfloor stretcher has a reduced cross-section area so that it can be connected to the base crossbeam by a dropped edge.

[0009] However, this reduced cross-sectional area results in a weak point in terms of resistance to stress during a frontal impact. Indeed, during a frontal impact, it produces a fold at the reduced section area, causing the floor to collapse under the weight of the battery modules. Description of the invention

[0010] The invention aims to address the problems of the prior art by proposing a hybrid or electric vehicle comprising a subframe structure with hollow-body underfloor stretchers providing better resistance in the event of a frontal impact, by preventing the underfloor stretcher from bending.

[0011] To this end, according to a first aspect of the invention, a hybrid or electric vehicle is proposed comprising a structure including a floor, a seat crossmember extending transversely under the floor along a battery compartment, and at least one subfloor stretcher extending longitudinally under the floor. The subfloor stretcher is hollow and has a constant cross-section.

[0012] According to the invention, the structure comprises a support box positioned on the seat cross member. The subfloor stretcher extends to the support box so as to present one end opposite the support box.

[0013] The invention thus provides a hybrid or electric vehicle comprising a subframe structure with hollow-body underfloor stretchers providing better resistance in the event of a frontal impact, by preventing the underfloor stretcher from bending.

[0014] This solution avoids the use of a hollow underfloor stretcher comprising a reduced section area connected to the base crossbeam.

[0015] The invention makes it possible to use a vehicle structure comprising underfloor stretchers and hollow support boxes, formed from stamped sheet metal instead of tubes, while obtaining equivalent results in frontal impact tests. The use of hollow bodies reduces the number of parts, manufacturing time, material savings (by reducing the thickness of the parts), and weight savings. It also increases battery range and extends battery life.

[0016] According to one embodiment, a space d is provided between the end of the underfloor stretcher and the support box.

[0017] Preferably, the space d is between 3 mm and 10 mm.

[0018] This space d allows for a gap to be formed between the end of the subfloor stretcher and the side support wall of the support box.

[0019] In a frontal collision, the gap is quickly filled. The end of the underfloor stretcher, which has a U-shaped or bridge-shaped cross-section, comes to rest against The side wall supports the support box. The support box acts as a stop for the underfloor stretcher.

[0020] According to another embodiment, the support box comprises a hollow body positioned opposite the base beam. The hollow body projects from the base beam in a direction opposite to the floor.

[0021] The support box can deform and absorb part of the shock because it is hollow. The underfloor stretcher is only slightly deformed and does not bend.

[0022] According to another embodiment, the support box comprises a base extending from a first end of the hollow body towards the battery compartment. The base is fixed to the floor by first fastening means.

[0023] The fact that the hollow body and the first means of fixing are distant allows the hollow body to act as a stop and possibly to be deformed during a frontal impact but without tearing off the first means of fixing and avoiding too much mechanical stress on the seat cross member.

[0024] According to another embodiment, the hollow body has a parallelepiped shape and includes a bottom wall at a second end, opposite the first end. The hollow body comprises four lateral walls connecting the base to the bottom wall, including a supporting lateral wall positioned opposite the end of the subfloor stretcher.

[0025] According to another embodiment, the lateral support wall is extended by a portion extending along a lateral wall of the seat cross member, towards the floor.

[0026] This solution improves the stop function because the portion is stopped by the side wall of the seat cross member during a frontal impact.

[0027] According to another embodiment, the end of the underfloor stretcher and the side support wall of the hollow body have an overlap height h between 50% and 100%.

[0028] This allows the hollow body to perfectly perform its function as a stop.

[0029] According to another embodiment, the vehicle includes a battery housed in the battery compartment and a mounting bracket comprising a first portion fixed to the base of the support box by the first fastening means and a second portion fixed to the battery.

[0030] The support box has two functions because it serves as a stop and also as an attachment point for fixing the battery.

[0031] According to another embodiment, the first fastening means comprise a spacer positioned between the base of the support box and the mounting bracket. The first fastening means comprise a screw having a threaded shank that fits into a hole provided in the mounting bracket and in the spacer to screw into a threaded hole provided on the base.

[0032] This provides a strong fastening means and allows the mounting tab to be at the height of the battery. brief description of the figures

[0033] Other features and advantages of the invention will become apparent from the following description, with reference to the accompanying figures, which illustrate:

[0034] [Fig-1]: a schematic view of a vehicle structure including a stretcher subfloor and a support box, according to one embodiment of the invention;

[0035] [Fig.2]: a detailed schematic view of the support box of [Fig.1] opposite the subfloor stretcher;

[0036] [Fig.3]: a detailed schematic view of the support box of [Fig.1] alone;

[0037] [Fig.4]: another detailed schematic view of the support box alone;

[0038] [Fig. 5]: A schematic view of a battery mounting tab attached to the box support.

[0039] For clarity, identical or similar elements are identified by identical reference signs throughout the figures. DETAILED description of a method of implementation

[0040] Fig. 1 illustrates a hybrid or electric vehicle 1 comprising a structure including a floor 2 and a seat cross member 4 extending transversely under the floor 2, along a battery compartment 5 in a transverse direction which is perpendicular to a direction of travel A of the vehicle 1.

[0041] The battery compartment 5 is intended to house a battery 42, which is commonly referred to as a "battery pack". The battery pack comprises several battery modules protected by a casing.

[0042] The structure comprises two stretchers 3a, each having a portion fixed to the floor 2 called the subfloor stretcher 3. Each subfloor stretcher 3 extends longitudinally along and under the floor 2 to the seat cross member 4. In other words, each subfloor stretcher 3 is fixed to an external face 26 of the floor 2 that faces the ground when the vehicle 1 is on the ground. Only one subfloor stretcher 3 is shown for the sake of simplicity.

[0043] The underfloor stretcher 3 is hollow and has a substantially constant cross-section to increase its strength and avoid areas of weakness in the event of a frontal impact.

[0044] The subfloor stretcher 3 is formed from a stamped and folded sheet metal. The subfloor stretcher 3 has a general U-shaped cross-section and two lateral edges 27 welded to the outer face 26 of the floor 2.

[0045] The subfloor stretcher 3 includes an end 7 positioned opposite a side wall 16 of the seat cross member 4, as illustrated in [Fig.2]. The end 7 has a U-shaped or bridge-shaped cross-section.

[0046] The structure includes a support box 6 positioned on an external face 28 of the seat cross member 4 and opposite an end 7 of the subfloor stretcher 3.

[0047] The support box 6 includes a hollow body 9 positioned opposite the seat cross member 4, in other words under the seat cross member 4. The hollow body 9 projects from the external face 28 of the seat cross member 4 in a direction opposite to the floor 2, i.e. towards the ground.

[0048] The support box 6 is formed from a sheet metal which is stamped to obtain the hollow body 9.

[0049] The support box 6 includes a base 8 extending from a first end 29 of the hollow body 9, towards the battery compartment 5. The base 8 is fixed to the floor 2 by first fixing means 20.

[0050] The hollow body 9 has a parallelepiped shape and includes a bottom wall 10 at a second end 30, opposite the first end 29. The hollow body 9 includes four lateral walls 11, 12, 13, 14, connecting the base 8 to the bottom wall 10, including a supporting lateral wall 11 positioned opposite the end 7 of the subfloor stretcher 3.

[0051] In figures 1 to 5, the hollow body 9 has the shape of a truncated pyramid. Other shapes are possible, such as cubic shapes.

[0052] The hollow body 9 includes a cavity 31, as illustrated in [Fig.3], and an opening 32 positioned opposite the external face 28 of the seat cross member 4.

[0053] Advantageously, a space d is provided between the end 7 of the subfloor stretcher 3 and the lateral support wall 11 of the support box 6, as illustrated in [Fig.2],

[0054] The space d is between 3 mm and 10 mm and preferably between 5 mm and 7 mm.

[0055] This space d allows a gap to be formed between the end 7 of the subfloor stretcher 3 and the lateral support wall 11 of the support box 6.

[0056] In a frontal impact, the gap is quickly closed and the end 7 of the subfloor stretcher 3 comes to rest against the lateral support wall 11 of the support box 6. The support box 6 can deform and absorb the impact because it is hollow. The subfloor stretcher 3 is only slightly deformed and does not bend.

[0057] For example, the support box 6 may have a square base 8 with a width 1 of 50 cm, as illustrated in [Fig. 4]. The height H1 of the hollow body 9 relative to the base 8 is 40 cm. The height H of the subfloor stretcher 3 is 70 cm. The width L of the subfloor stretcher 3 is 60 cm.

[0058] The supporting side wall 11 is extended by a portion 15 extending along the side wall 16 of the seat cross member 4, towards the floor 2. The side wall 16 of the cross member 4 is oriented towards the front of vehicle 1, i.e. towards the direction of advancement A.

[0059] The height H1 of the hollow body 9 is configured so that during a frontal impact following the direction of travel A of the vehicle 1, the end 7 of the underfloor stretcher 3 comes to rest on 50% to 100% of the height of the lateral support wall 11, extended by the portion 15. The overlap height h between the end 7 of the underfloor stretcher 3 and the lateral support wall 11 is then between 50% and 100%.

[0060] Preferably, the overlap height h is 70%.

[0061] The overlap height h between the end 7 of the subfloor stretcher 3 and the lateral support wall 11 of the support box 6, including the portion 15, is 35 cm, for example.

[0062] The support box 6 includes a rim 17 extending in a direction opposite to the seat cross member 4 and following the direction of advancement A.

[0063] The rim 17 extends along a lateral wall 12 of the hollow body 9 and of the base 8. The rim 17 is formed by a folding of a part of the base 8.

[0064] Alternatively, the support box 6 includes an extension 33 formed by folding a part of the base 8 which is directed in the opposite direction to the rim 17.

[0065] The vehicle 1 includes a battery 42 housed in the battery compartment 5 and a mounting bracket 18 comprising a first portion 21 fixed to the base 8 of the support box 6 by the first fixing means 20 and a second portion 22 fixed to the battery 42, as illustrated in [Fig.5].

[0066] The fixing tab 18 has a rectangular shape and includes two opposing edges 34, projecting from a central part 35 and allowing to reinforce the mechanical hold of the fixing tab 18.

[0067] The first portion 21 is positioned at a first end 36 of the fixing tab 18 and the second portion 22 is positioned at a second end 37 of the fixing tab 18.

[0068] The first fastening means 20 are positioned at the first end 36 of the fastening tab 18.

[0069] The first fixing means 20 comprise a cylindrical spacer 23 positioned between the base 8 of the support box 6 and the fixing lug 18. The spacer 23 extends along the hollow body 9, substantially over its entire height Hl, in a direction opposite to the seat cross member 4.

[0070] The first fixing means 20 include a screw 24 having a threaded rod that fits into an orifice 25 provided in the fixing tab 18 and in the spacer 23 to screw into a threaded orifice provided on the base 8.

[0071] To fix the fixing bracket 18 to the support box 6, the screw 24 is screwed into the threaded hole of the base 8 so that a screw head 38 tightens the fixing bracket 18 against the spacer 23.

[0072] The mounting bracket 18 includes second fastening means (not shown) for attaching the second end 37 of the mounting bracket 18 to the battery 42. The second fastening means include a screw that fits into a second hole 40 provided at the second end 37 of the mounting bracket 18 and screws into a threaded hole provided in the battery housing 42.

[0073] The fixing lug 18 extends along the direction of advancement A and is positioned substantially at the same height as the bottom wall 10 of the hollow body 9. The fixing lug 18 is distant from the hollow body 9.

[0074] Alternatively, the mounting bracket 18 may include a fin 41 attached to the battery 42.

[0075] Alternatively, the space d is removed and the end 7 of the subfloor stretcher 3 is in contact with the lateral support wall 11 of the support box 6.

[0076] Naturally, the invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different embodiments of the invention without departing from the scope of the invention.

Claims

Demands

1. Hybrid or electric vehicle (1) comprising a structure (la) having a floor (2), a seat cross member (4) extending transversely under the floor (2) along a battery compartment (5) and at least one subfloor stretcher (3) extending longitudinally under the floor (2), the subfloor stretcher (3) being hollow and having a constant cross section, characterized in that the structure (la) comprises a support box (6) positioned on the seat cross member (4), the subfloor stretcher (3) extending to the support box (6) so as to have one end (7) opposite the support box (6) and in that a space d is provided between the end (7) of the subfloor stretcher (3) and the support box (6).

2. Vehicle (1) according to claim 1, characterized in that the space d is between 3 mm and 10 mm.

3. Vehicle (1) according to any one of claims 1 to 2, characterized in that the support box (6) comprises a hollow body (9) positioned opposite the seat cross member (4), the hollow body (9) projecting from the seat cross member (4) in a direction opposite to the floor (2).

4. Vehicle (1) according to claim 3, characterized in that the support box (6) comprises a base (8) extending from a first end (29) of the hollow body (9), towards the battery compartment (5), the base (8) being fixed to the floor (2) by first fixing means (20).

5. Vehicle (1) according to claim 4, characterized in that the hollow body (9) has a parallelepiped shape and comprises a bottom wall (10) at a second end (30), opposite the first end (29), and four side walls (11, 12, 13, 14) connecting the base (8) to the bottom wall (10), of which a supporting side wall (11) is positioned opposite the end (7) of the subfloor stretcher (3).

6. Vehicle (1) according to claim 5, characterized in that the side support wall (11) is extended by a portion (15) extending along a side wall (16) of the seat cross member (4), towards the floor (2).

7. Vehicle (1) according to claim 6, characterized in that the end (7) of the underfloor stretcher (3) and the supporting side wall (11) of the hollow body (9) have an overlap height h between 50% and 100%.

8. Vehicle (1) according to any one of claims 4 to 7, characterized in that it comprises a battery (42) housed in the battery compartment (5) and a mounting bracket (18) comprising a first portion (21) fixed to the base (8) of the support box (6) by the first fastening means (20) and a second portion (22) fixed to the battery (42).

9. Vehicle (1) according to claim 8, characterized in that the first fastening means (20) comprise a spacer (23) positioned between the base (8) of the support box (6) and the fastening tab (18) and a screw (24) having a threaded rod that fits into an orifice (25) provided in the fastening tab (18) and in the spacer (23) to screw into a threaded orifice provided on the base (8).

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