Reinforced rear body structure for motor vehicle

Abstract

The invention relates to a rear body structure (1) for a motor vehicle, the rear structure (1) comprising, on either side of the rear body structure (1) relative to a transverse axis (Y), a rear side member (12) extending along a longitudinal axis (X) of the motor vehicle arranged along a lateral side of said motor vehicle, a rear side member (11) adjacent to the rear side member (12), a rear cross member (13) extending transversely from the rear side member (12), and a reinforcement member (14) allowing subsequent support of a jack, the reinforcement member (14) being associated with the rear side member (11). Advantageously, the reinforcement member (14) is fixed rigidly to both the rear side member (12) and the rear side member (11) by means of a single fastening member (15). Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: Reinforced rear body structure for a motor vehicle

[0001] The technical context of the present invention is that of the structural elements of a motor vehicle, and in particular those relating to its chassis. More particularly, the invention relates to a rear body structure for a motor vehicle, having mechanical reinforcement.

[0002] In the state of the art, a rear body structure for a motor vehicle is known, the rear body structure comprising:

[0003] - two rear side members each extending along a longitudinal axis of the vehicle automobile and each arranged on a lateral side of said motor vehicle, relative to a transverse axis,

[0004] - two rear axle supports of the motor vehicle, each arranged on one side lateral of said motor vehicle, relative to the transverse axis, each rear axle support being fixed securely to the corresponding rear side member,

[0005] - a rear cross member extending transversely between the two rear side members, in front of the rear axle supports, the rear cross member being securely attached to the rear side members by means of cross member end pieces secured to the lateral ends of said rear cross member.

[0006] In order to make it possible to lift such a rear body structure using a jack, the use of a reinforcing member associated with one of the rear side members is also known. Such a reinforcing member takes the form of a reinforced metal sheet which has a jack-bearing area. Thus, in order to lift such a rear body structure, the jack can be inserted under one of the side members and be brought to bear against the bearing area of ​​the reinforcing member. When the jack is subsequently used, the reinforcing member guarantees sufficient mechanical rigidity of the body structure at the bearing area.

[0007] However, in the context of the development of new electrified motor vehicles, the mass contribution involved by the location of the electric traction batteries in the rear zone of the rear body structure leads to increased forces, in particular when lifting said rear body structure using a jack. There is then a need for reinforcement at the level of the lifting zone and the reinforcement member.

[0008] The object of the present invention is to propose a new rear body structure in order to respond at least to a large extent to the preceding problems and to further lead to other advantages.

[0009] Another aim of the invention is to improve the strength of the reinforcing member.

[0010] Another object of the invention is to reinforce the rigidity of the rear body structure. at the level of the reinforcement organ.

[0011] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a rear body structure for a motor vehicle, the rear body structure comprising:

[0012] - two rear side members each extending along a longitudinal axis of the vehicle automobile and each arranged on a lateral side of said motor vehicle, relative to a transverse axis;

[0013] - two rear side members each extending along the longitudinal axis, each side member rear being associated with a different rear side member, so that an inner rebate of the rear side member is fixed securely to the corresponding rear side member;

[0014] - a rear cross member extending transversely between the two rear side members, in front of the rear axle supports, the rear cross member being securely attached to the rear side members by means of cross member end pieces secured to the lateral ends of said rear cross member;

[0015] - at least one reinforcing member allowing the support of a lifting jack of the motor vehicle, the at least one reinforcing member being fixed securely to one of the rear side members and to the corresponding rear side member.

[0016] According to the invention, the reinforcement member, the rear spar and the corresponding rear spar are fixed together by means of the same fixing member.

[0017] In the context of the present invention, a longitudinal axis, a lateral axis and a vertical axis are defined relative to the motor vehicle on which the rear body structure according to the first aspect of the invention is intended to be mounted. More particularly, the transverse axis is understood as a direction taken between a lateral side of the motor vehicle and an opposite lateral side of said motor vehicle. In other words, the transverse axis is understood as a direction which extends from a passenger side of the motor vehicle to a driver's side of said motor vehicle, or vice versa. The adjectives lateral, inboard and outboard refer to such a transverse axis. Furthermore, the longitudinal axis extends as being taken along a direction which extends from front to rear or from back to front of the motor vehicle. The longitudinal axis is perpendicular to the transverse axis.The adjectives frontal, front and rear refer to this longitudinal axis. Finally, the vertical axis is understood to be taken along an axis which extends from the wheels of the motor vehicle and towards the roof of said motor vehicle, or vice versa, the vertical axis being simultaneously perpendicular to the transverse axis and to the longitudinal axis. The adjectives . above and below, or lower and upper refer to this vertical axis.

[0018] In the context of the present invention, the rear side member forms a prismatic span which extends relative to the longitudinal axis of the motor vehicle, at each lateral side of said motor vehicle. The rear side members form structural elements of the motor vehicle to which other parts of the motor vehicle are attached. The rear side members thus provide the rigidity necessary for the operation of the motor vehicle, during driving sequences, but also in the event of an accident in order to transmit the forces resulting from said impact towards absorption devices or towards running gear of the motor vehicle for example. The rear side members extend behind an engine compartment of the motor vehicle.

[0019] In the context of the present invention, the rear side member forms a prismatic span which extends relative to the longitudinal axis of the motor vehicle, at each lateral side of said motor vehicle and adjacent to the corresponding rear side member. The rear side members form structural elements of the motor vehicle to which other parts of the motor vehicle are attached. The rear side members thus provide the rigidity necessary for the operation of the motor vehicle, during driving sequences, but also in the event of an accident in order to transmit the forces resulting from said impact towards absorption devices or towards the running gear of the motor vehicle for example. The rear side members extend outside the rear side members, relative to the transverse axis of the motor vehicle.

[0020] In the context of the present invention, the inner rebate of the rear side member forms an inner wall of said rear side member, located on one side of the passenger compartment of the motor vehicle, relative to the transverse axis. In other words, the inner rebate of the rear side member delimits said rear side member on the side of the passenger compartment of the motor vehicle. The inner rebate of the rear side member extends mainly along the longitudinal axis and the vertical axis. In the context of the present invention, the inner rebate is connected to the corresponding rear side member.

[0021] In the context of the present invention, the rear crossmember forms a prismatic span which extends relative to the transverse axis of the motor vehicle, between the two rear side members of said motor vehicle. The rear crossmember forms a structural element of the motor vehicle to which it is attached. The rear crossmember contributes to providing the necessary rigidity to the chassis of the motor vehicle in order to ensure optimal operation during driving sequences or in the event of an accident, in order to transmit the forces resulting from said impact towards absorption devices. The rear crossmember extends rearward at the level of a rear trunk of the motor vehicle.

[0022] In the context of the present invention, the rear side members, the rear cross member and the rear side members together delimit a location for electric traction batteries of the electrified motor vehicle.

[0023] In the context of the present invention, the reinforcing member is an interface part for a jack for lifting the rear body structure. The reinforcing member thus makes it possible to prevent, at a zone where the jack bears against the rear body structure, the facing part from deforming under the effect of the weight of the rear body structure and the pressure exerted by the jack on said rear structure. Advantageously, the rear body structure comprises such a reinforcing member on each lateral side, each reinforcing member being associated with one and only one rear side member.

[0024] In the context of the present invention, the fixing member is configured to establish a fixed fixing of several parts together, namely the rear side member, the rear side member and the corresponding reinforcing member. Thus, the fixing member makes it possible to reinforce the rigidity of the body structure, at this mechanical interface. In particular, the fact that the fixing member simultaneously associates and connects the three aforementioned parts through a single fixing makes it possible to obtain a robust and viable fixing more effectively.Such simultaneous fixing of these three parts makes it possible to reinforce the hold of said fixing in the event of use of a jack collaborating with the reinforcement member, such reinforcement being made necessary due to a relative increase in the weight of the rear body structure in the event in particular, and in a non-limiting manner, of integration of electric traction batteries between the rear side members and the rear cross member.

[0025] The rear body structure according to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0026] - each reinforcing member takes the form of a shaped metal sheet which extends at the level of the rear side member, behind a rear axle support of the motor vehicle, relative to the longitudinal axis. The reinforcing member extends across the rear side member. The reinforcing member is preferably formed of steel in order to provide high rigidity;

[0027] - the rear side member has a flap which extends against the inner rebate of the corresponding rear side member. The flap of the rear side member forms an angle relative to said rear side member, so as to facilitate the support and fixing of said rear side member against the corresponding rear side member, and more particularly against its inner rebate;

[0028] - the fixing member is configured to establish a permanent fixing of the flap of the rear spar against the inner rebate of the corresponding rear spar and the corresponding reinforcing member. Permanent attachment means that the rear spar and / or the rear spar and / or the reinforcing member cannot be separated from each other without affecting their integrity, i.e. without damaging or breaking them. This advantageous configuration makes it possible to establish a stronger, more rigid and more robust attachment;

[0029] - generally, the fixing member is configured to establish a fixing hot between the aforementioned parts. In particular, the fixing member is configured to connect the parts together by local fusion of the rear spar and the rear spar and the corresponding reinforcement member, together;

[0030] - in particular, the fixing member comprises at least one triple welding point thickness. The at least one welding point is located at an overlapping zone of the rear spar, the rear spar, and the corresponding reinforcement member;

[0031] - the fixing member comprises a first triple-thickness welding point located on the side of a front edge of the reinforcement member, and a second triple-thickness weld point located on the side of a rear edge of the reinforcement member. This advantageous configuration makes it possible to secure the reinforcement member to the rear spar and to the rear spar, simultaneously, in a more efficient and more robust manner;

[0032] - the at least one reinforcing member comprises a first support zone located on the side of the front edge and a second support zone, located on the side of the rear edge, the first support zone and the second support zone bearing against the inner rebate of the corresponding rear spar, and opposite the flap of the corresponding rear spar. According to a preferred embodiment, the support zone forms a protrusion which extends projecting from the reinforcing member, in the direction of the inner rebate of the rear spar. The protrusion thus forms a platform, preferably flat, which allows a complementarity of shape with the inner lining of the rear spar and with the rear spar, and more particularly with its flap, located opposite.

[0033] According to a second aspect of the invention, there is provided a motor vehicle comprising a rear structure in accordance with the first aspect of the invention or according to any of its improvements.

[0034] Advantageously, the motor vehicle is of the electrified type and for this purpose comprises one or more electric traction batteries. Preferably, the electric traction battery(ies) rest(s) on the rear body structure, between the two side members and behind the rear cross member, relative to the longitudinal axis.

[0035] In the context of the present invention, the electric traction battery is a high voltage electric battery capable of generating a direct voltage of at least 300V, for example equal to 400V or 800V. Generally speaking, the electric traction battery is configured to supply electrical energy to an electric machine generating engine torque on a powertrain of the motor vehicle.

[0036] In the context of the present invention, an electrified motor vehicle is of the type of an electric or hybrid motor vehicle. Generally, a powertrain of such an electrified motor vehicle is rotated by an electric machine, electrically powered by the electric traction battery, in order to generate a motor torque used to set the motor vehicle in motion. Additionally or alternatively, the electric machine is configured to recover mechanical energy from the powertrain and convert it into electrical energy, thus producing a braking torque on said powertrain and making it possible to recharge the electric traction battery.

[0037] Of course, the present invention, through any of its aspects, is not limited to electrified vehicles alone, although it finds in their development a particularly interesting destination due to the increase in weight of such electrified motor vehicles due to the integration of their electric traction batteries.

[0038] Various embodiments of the invention are provided, integrating according to all of their possible combinations the different optional characteristics set out here.

[0039] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0040] [Fig.l] illustrates a three-dimensional overall view of an exemplary embodiment of a rear body structure in accordance with the first aspect of the invention;

[0041] [Fig-2] illustrates a detail view of the rear body structure illustrated in the [Fig.l] and in which the rear spar is shown in transparency.

[0042] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0043] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0044] In the figures, the elements common to several figures retain the same reference.

[0045] In FIGURES 1 and 2, a longitudinal axis X, a lateral axis and a vertical axis Z are defined relative to the motor vehicle on which the rear body structure 1 according to the first aspect of the invention is intended to be mounted.

[0046] More particularly, the transverse axis Y is understood as a direction taken between a lateral side of the motor vehicle and an opposite lateral side of said motor vehicle. In other words, the transverse axis Y is understood in a direction which extends from a passenger side of the motor vehicle to a driver's side of said motor vehicle, or vice versa. The adjectives lateral, interior and exterior refer to such a transverse axis Y.

[0047] Furthermore, the longitudinal axis X extends as taken along a direction that extends from front to rear or from back to front of the motor vehicle. The longitudinal axis X is perpendicular to the transverse axis Y. The adjectives frontal, front and rear refer to this longitudinal axis X.

[0048] Finally, the vertical axis Z is understood as being taken along an axis which extends from the wheels of the motor vehicle and towards the roof of said motor vehicle, or vice versa, the vertical axis Z being simultaneously perpendicular to the transverse axis Y and to the longitudinal axis X. The adjectives above and below, or lower and upper refer to this vertical axis Z.

[0049] With reference to FIGURES 1 and 2, the invention relates to a rear body structure 1 for a motor vehicle, the rear body structure 1 comprising:

[0050] - two rear side members 12 each extending along a longitudinal axis X of the motor vehicle and each arranged on a lateral side of said motor vehicle, relative to a transverse axis Y. Each rear side member 12 thus takes the form of a prismatic beam which extends along one of the lateral sides of the motor vehicle;

[0051] - two rear side members 11 each extending along the longitudinal axis X, each rear side member 11 being associated with a different rear side member 12, so that an inner rebate 111 of the rear side member 11 is fixed integrally to the corresponding rear side member 12. Each rear side member 11 thus takes the form of a prismatic beam which extends along one of the lateral sides of the motor vehicle. The rear side member 11 extends along the rear side member 12 with which it is associated, bordering it on the outside, relative to the transverse axis Y;

[0052] - a rear cross member 13 extending transversely between the two side members rear 12, in front of the rear axle supports, the rear cross member 13 being fixed solidly- clearly to the rear side members 12 by means of cross member end pieces secured to the lateral ends of said rear cross member 13. The rear cross member 13 has the shape of a prismatic beam which extends across the two rear side members 12. The rear cross member 13 is securely fixed to the rear side members 12 by any means, and / or preferably by welding or bolting;

[0053] - at least one reinforcing member 14 allowing the support of a lifting jack of the motor vehicle at a support zone 141, the at least one reinforcing member 14 being fixed integrally to one of the rear side members 11 and to the corresponding rear side member 12.

[0054] According to an essential characteristic of the invention, each at least one reinforcing member 14, the rear spar 11 and the corresponding rear spar 12 are fixed together by means of the same fixing member 15.

[0055] In particular, the fixing member 15 is configured to establish a simultaneous, i.e. joint, fixing of the rear spar 12 with the associated rear spar 11 and the associated reinforcing member 14. As visible in [Fig.2], at the level of the fixing member 15, the rear spar 12, the associated rear spar 11 and the associated reinforcing member 14 are superimposed on each other in order to allow a common fixing.

[0056] For this purpose, the rear spar lining 12 comprises a flap 121 which extends against an inner rebate 111 of the rear spar 12. Thus, the fixing member 15 is configured to fix together, in a fixed manner and through a common connection, a lower part of the rear spar 11, relative to the vertical axis Z, a lower part of the associated reinforcing member 14, and the flap 121 of the associated rear spar 12. For this purpose, and as visible in [Fig. 2], the flap 121, the rear spar 11 and the associated reinforcing member 14 are advantageously superimposed at the level of the fixing member 15.

[0057] In a particularly preferred manner, the fixing member 15 is configured to establish a permanent fixing between the rear spar 12, the rear spar 11 and the associated reinforcing member 14. More particularly, the fixing member 15 is configured to establish a fixing by local fusion of the rear spar 12 and the rear spar 11 and the associated reinforcing member 14, together. The fixing member 15 thus comprises at least one weld point 151, 152 in triple thickness through the flap 121 of the rear spar 12, the rear spar 11 and the associated reinforcing member 14, and preferably two weld points 151, 152 as indicated in [Fig.2].The two welding points 151, 152 are distributed along the longitudinal axis X on a lower edge of the reinforcing member 14, located opposite the flap 121 of the reinforcing member 14, at the level of a superposition zone of the rear spar 11, said flap 121 and the reinforcing member 14.

[0058] More particularly, advantageously, the fixing member 15 comprises a first welding point 151 located on a front part of the lower edge of the reinforcing member 14, and a second welding point 152 located at a rear part of the lower edge of the reinforcing member 14. This advantageous configuration makes it possible to effectively fix together the rear spar 11, the associated rear spar 12 and the associated reinforcing member 14.

[0059] In particular, each reinforcing member 14 comprises a first bearing zone located on the front edge side and a second bearing zone, located on the rear edge side, the first bearing zone and the second bearing zone bearing against the inner rebate 111 of the corresponding rear spar 11, and facing the flap 121 of the corresponding rear spar 12. Each bearing zone forms a protrusion which extends from the reinforcing member 14 and which forms a bearing platform against the inner rebate 111 of the rear spar 12 located opposite, and its flap 121. Consequently, the first weld point 151 located on the first bearing zone of the reinforcing member 14 makes it possible to fix together the flap 121 of the rear spar 12, the rear spar 11 located opposite and said reinforcing member 14.Similarly, the second welding point 152 located on the second support zone of the reinforcing member 14 makes it possible to securely fix together the flap 121 of the rear spar 12, the rear spar 11 located opposite and said reinforcing member 14.

[0060] The rear body structure 1 thus delimits, between each rear side member 11 and behind the rear cross member 13, one or more housings 17 intended to allow the attachment of one or more electric traction batteries.

[0061] Each reinforcing member 14 takes the form of a stamped and shaped sheet metal so as to extend between an upper edge and a lower edge of the rear spar 11 with which it is associated. In the context of the present invention, the reinforcing member 14 is fixed to the rear spar 11 and at its lower edge by means of the fixing member 15. The reinforcing member 14 has a transverse section, taken perpendicular to the longitudinal axis X, in the shape of an "S". the bearing zone 141 of the reinforcing member 14 comprises a plane which extends in an inclined manner to the rear spar 11, so as to facilitate the subsequent bearing of a jack.

[0062] Advantageously, the fixing member 15 associated with the reinforcing member 14 is located on either side of the bearing zone 141 of the reinforcing member 14. In other words, relative to the vertical axis Z, the fixing member 15 is located at a lower part of the reinforcing member 14. The lower part of the reinforcing member 14 bears against the inner rebate 111 of the associated rear side member 11.

[0063] In summary, the invention relates to a rear body structure 1 for a vehicle motor vehicle, the rear structure 1 comprising, on either side of the rear body structure 1 relative to a transverse axis Y, a rear longitudinal member 12 extending along a longitudinal axis X of the motor vehicle arranged along a lateral side of said motor vehicle, a rear longitudinal member 11 adjacent to the rear longitudinal member 12, a rear cross member 13 extending transversely from the rear longitudinal member 12, and a reinforcing member 14 allowing subsequent support of a jack, the reinforcing member 14 being associated with the rear longitudinal member 11. Advantageously, the reinforcing member 14 is fixed integrally to both the rear longitudinal member 12 and the rear longitudinal member 11 by means of the same fixing member 15.

[0064] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

Claims

1. Rear body structure (1) for a motor vehicle, the rear body structure (1) comprising: - two rear side members (12) each extending along a longitudinal axis (X) of the motor vehicle and each arranged on a lateral side of said motor vehicle, relative to a transverse axis (Y); - two rear side members (11) each extending along the longitudinal axis (X), each rear side member (11) being associated with a different rear side member (12), so that an inner rebate (111) of the rear side member (11) is fixedly attached to the corresponding rear side member (12); - a rear cross member (13) extending transversely between the two rear side members (12), in front of the rear axle supports, the rear cross member (13) being fixed integrally to the rear side members (12) by means of cross member end pieces integral with the lateral ends of said rear cross member (13);- at least one reinforcing member (14) allowing the support of a lifting jack of the motor vehicle, the at least one reinforcing member (14) being fixed integrally to one of the rear side members (11) and to the corresponding rear side member (12); characterized in that the reinforcing member (14), the rear side member (11) and the corresponding rear side member (12) are fixed integrally together by means of the same fixing member (15).;

2. Rear structure (1) according to the preceding claim, in which the rear spar (12) comprises a flap (121) which extends against the inner rebate (111) of the corresponding rear spar (11).

3. Rear structure (1) according to the preceding claim, in which the fixing member (15) is configured to establish a permanent fixing of the flap (121) of the rear spar (12) against the inner rebate (111) of the corresponding rear spar (11) and the corresponding reinforcing member (14).

4. Rear structure (1) according to any one of the preceding claims, in which the fixing member (15) comprises at least one triple-thickness weld point (151, 152).

5. Rear structure (1) according to the preceding claim, in which the fixing member (15) comprises a first triple-thickness weld point (151) located on the side of a front edge of the reinforcing member (14), and a second triple-thickness weld point (152) located on the side of a rear edge of the reinforcing member (14).

6. Rear structure (1) according to the preceding claim taken in combination with claim 2, in which the at least one reinforcing member (14) comprises a first support zone located on the front edge side and a second support zone, located on the rear edge side, the first support zone and the second support zone bearing against the inner rebate (111) of the corresponding rear spar (11), and opposite the flap (121) of the corresponding rear spar (12).

7. Motor vehicle comprising a rear body structure (1) according to any one of the preceding claims.

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