Reinforced rear body structure for a 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 rail (12) extending along a longitudinal axis (X) of the motor vehicle and arranged along a lateral side of the motor vehicle, a rear longitudinal member (11) adjacent to the rear side rail (12), a rear cross member (13) extending transversely from the rear side rail (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 rigidly connected both to the rear side rail (12) and to the rear longitudinal member (11) by means of the same attachment member (15).

Description

Description Title of the invention: Reinforced rear body structure for motor vehicle [1] The present invention claims priority from French application 2300766 filed on January 27, 2023, the content of which (text, drawings and claims) is incorporated herein by reference. [2] 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 specifically, the invention relates to a rear body structure for a motor vehicle, featuring mechanical reinforcement. [3] In the prior art, a rear body structure for a motor vehicle is known, the rear body structure comprising: [4] - two rear side members, each extending along a longitudinal axis of the motor vehicle and each positioned on a lateral side of said motor vehicle, relative to a transverse axis, [5] - two rear axle supports of the motor vehicle, each disposed on one lateral side of said motor vehicle, relative to the transverse axis, each rear axle support being fixed securely to the corresponding rear side member, [6] - a rear cross member extending transversely between the two rear side members, in front of the rear axle supports, the rear cross member being fixed securely to the rear side members by means of cross member ends fixed to the lateral ends of said rear cross member. [7] To enable the lifting of such a rear body structure using a jack, a reinforcement element attached to one of the rear side members is also known. This reinforcement element takes the form of a reinforced metal plate with a jacking point. Thus, to lift such a rear body structure, the jack can be inserted under one of the side members and placed against the jacking point of the reinforcement element. During subsequent use of the jack, the reinforcement element ensures sufficient mechanical rigidity of the body structure at the jacking point. [8] However, in the context of the development of new electrified motor vehicles, the added mass resulting from the location of the electric traction batteries in the rear area of ​​the rear body structure leads to increased stresses, particularly when lifting said rear body structure with a jack. There is therefore a need for reinforcement in the lifting area and the reinforcing element. [9] The present invention aims to propose a new rear body structure in order to address at least largely the previous problems and to lead to further advantages.

[0010] Another aim of the invention is to improve the strength of the reinforcing element.

[0011] Another objective of the invention is to reinforce the rigidity of the rear body structure at the level of the reinforcement element.

[0012] 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:

[0013] - two rear side members each extending along a longitudinal axis of the motor vehicle and each positioned on a lateral side of said motor vehicle, relative to a transverse axis;

[0014] - two rear longitudinal members each extending along the longitudinal axis, each rear longitudinal member being associated with a different rear longitudinal member, so that an internal rebate of the rear longitudinal member is fixed securely to the corresponding rear longitudinal member;

[0015] - a rear crossmember extending transversely between the two rear side members, in front of the rear axle supports, the rear crossmember being fixed securely to the rear side members by means of crossmember ends attached to the lateral ends of said rear crossmember;

[0016] - at least one reinforcing element allowing the support of a lifting jack for the motor vehicle, at least one reinforcing element being fixed securely to one of the rear longitudinal members and to the corresponding rear longitudinal member.

[0017] According to the invention, the reinforcing member, the rear longitudinal member and the corresponding rear longitudinal member are fixed together by means of the same fastening member.

[0018] In the context of the present invention, a longitudinal axis, a lateral axis, and a vertical axis are defined with respect to the motor vehicle on which the rear body structure conforming to the first aspect of the invention is intended to be mounted. More specifically, the transverse axis is understood as a direction taken between one 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 extending from a passenger side of the motor vehicle to a driver's side of said motor vehicle, or vice versa. The adjectives lateral, inside, and outside refer to such a transverse axis. Furthermore, the longitudinal axis is understood as being taken along a direction extending from front to rear or from rear to front of the motor vehicle. The longitudinal axis is perpendicular to the transverse axis.The adjectives front, front, and rear refer to this longitudinal axis. Finally, the vertical axis is understood as being taken along a line extending from the wheels of the motor vehicle to the roof of said motor vehicle, or vice versa, the vertical axis being simultaneously perpendicular to the transverse axis and the longitudinal axis. The adjectives above and below, or lower and upper, refer to this vertical axis.

[0019] In the context of the present invention, the rear side member forms a prismatic span extending relative to the longitudinal axis of the motor vehicle, at each lateral side of said motor vehicle. The rear side members are 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, both during driving sequences and in the event of an accident, in order to transmit the forces resulting from said impact towards absorption devices or to the vehicle's running gear, for example. The rear side members extend behind an engine compartment of the motor vehicle.

[0020] In the context of the present invention, the rear side member forms a prismatic span that extends relative to the longitudinal axis of the motor vehicle, at each lateral side of the motor vehicle and adjacent to the corresponding rear side member. The rear side members are structural elements of the motor vehicle to which other vehicle parts are attached. The rear side members provide the rigidity necessary for the vehicle's operation during driving, but also in the event of an accident, in order to transmit the forces resulting from the impact towards shock absorbers or the vehicle's suspension components, for example. The rear side members extend beyond the rear side members, relative to the vehicle's transverse axis.

[0021] 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 vehicle's passenger compartment, 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 vehicle's passenger compartment. The inner rebate of the rear side member extends primarily along the longitudinal and vertical axes. In the context of the present invention, the inner rebate is connected to the corresponding rear side member.

[0022] In the context of the present invention, the rear crossmember forms a prismatic span extending 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 motor vehicle's chassis to ensure optimal operation during driving or in the event of an accident, in order to transmit the forces resulting from said impact towards the shock-absorbing devices. The rear crossmember extends rearward at the level of the rear trunk of the motor vehicle.

[0023] In the context of the present invention, the rear side members, the rear cross member and the rear side members together define a location for electric traction batteries of the electrified motor vehicle.

[0024] In the context of the present invention, the reinforcing element is an interface piece for a jack used to lift the rear body structure. The element This reinforcement prevents the corresponding part from deforming under the weight of the rear body structure and the pressure exerted by the jack on said structure, at the point where the jack rests against it. Advantageously, the rear body structure includes such a reinforcement element on each lateral side, each reinforcement element being associated with one and only one rear longitudinal member.

[0025] In the context of the present invention, the fastening element is configured to establish a rigid connection between several parts, namely the rear side member, the rear side member, and the corresponding reinforcement element. Thus, the fastening element increases the rigidity of the body structure at this mechanical interface. In particular, the fact that the fastening element simultaneously connects and links the three aforementioned parts through a single fastening allows for a more robust and durable connection.Such simultaneous fixing of these three parts makes it possible to strengthen the holding of said fixing in the event of the use of a jack collaborating with the reinforcing element, such reinforcement being made necessary by a relative increase in the weight of the rear body structure in the event in particular, and without limitation, of integration of electric traction batteries between the rear longitudinal members and the rear cross member.

[0026] The rear body structure conforming 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:

[0027] - Each reinforcing element takes the form of a shaped metal sheet extending along the rear side member, behind a rear axle support of the motor vehicle, relative to the longitudinal axis. The reinforcing element extends across the rear side member. The reinforcing element is preferably made of steel to provide high rigidity;

[0028] - The rear side member has a flap that extends against the inner groove of the corresponding rear side member. The flap of the rear side member forms an angle with respect to said rear side member, so as to facilitate support and the fixing of said rear longitudinal member against the corresponding rear longitudinal member, and more particularly against its inner rebate;

[0029] - The fastening element is configured to permanently attach the rear side member flap to the inner groove of the corresponding rear side member and the corresponding reinforcement element. Permanent attachment means that the rear side member and / or the rear side member and / or the reinforcement element cannot be separated from each other without compromising their integrity, i.e., without damaging or breaking them. This advantageous configuration allows for a stronger, more rigid, and more robust attachment;

[0030] - In general, the fastening element is configured to establish a hot connection between the aforementioned parts. In particular, the fastening element is configured to join the parts together by local fusion of the rear side member and the rear side member and the corresponding reinforcement element, together;

[0031] - in particular, the fastening element includes at least one triple-thickness weld point. At least one weld point is located at an overlap zone of the rear longitudinal member, the rear longitudinal member, and the corresponding reinforcing element;

[0032] - The fastening element comprises a first triple-thickness weld point located on the side of a front edge of the reinforcing element, and a second triple-thickness weld point located on the side of a rear edge of the reinforcing element. This advantageous configuration allows the reinforcing element to be joined to the rear longitudinal member and to the rear longitudinal member simultaneously, in a more efficient and robust manner;

[0033] - at least one reinforcing element comprises a first bearing area located on the front edge and a second bearing area located on the rear edge, the first and second bearing areas bearing against the inner rebate of the corresponding rear side member and opposite the flap of the corresponding rear side member. In a preferred embodiment, the bearing area forms a protrusion extending beyond the reinforcing element towards the inner rebate of the rear side member. The protrusion thus forms a platform, preferably flat, which allows for complementary shapes. with the inner lining of the rear side member and with the rear side member, and more particularly with its flap, located opposite.

[0034] According to a second aspect of the invention, a motor vehicle is proposed comprising a rear structure conforming to the first aspect of the invention or to any one of its improvements.

[0035] Advantageously, the motor vehicle is of the electrified type and, for this purpose, includes one or more electric traction batteries. Preferably, the electric traction battery(ies) are located on the rear body structure, between the two longitudinal members and behind the rear crossmember, relative to the longitudinal axis.

[0036] In the context of the present invention, the traction battery is a high-voltage electric battery capable of generating a direct current voltage of at least 300V, for example, 400V or 800V. Generally, the traction battery is configured to supply electrical power to an electric machine that generates torque on the traction system of the motor vehicle.

[0037] In the context of the present invention, an electrified motor vehicle is of the type of an electric or hybrid motor vehicle. Generally, the drivetrain of such an electrified motor vehicle is rotated by an electric machine, powered by the traction battery, in order to generate motor torque for propelling the motor vehicle. Complementarily or alternatively, the electric machine is configured to recover mechanical energy from the drivetrain and convert it into electrical energy, thereby producing braking torque on said drivetrain and recharging the traction battery.

[0038] Of course, the present invention, through any of its aspects, is not limited to electrified vehicles alone, although it finds a particularly interesting application in their development due to the increase in weight of such electrified motor vehicles due to the integration of their electric traction batteries.

[0039] Various embodiments of the invention are envisaged, incorporating, according to all their possible combinations, the different optional features described herein.

[0040] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the attached schematic drawings on the other hand, in which:

[0041] [Fig.1] illustrates a three-dimensional overview of an example of the realization of a rear body structure conforming to the first aspect of the invention;

[0042] [Fig.2] illustrates a detailed view of the rear body structure shown in FIGURE 1 and in which the rear side member is shown in transparency.

[0043] Of course, the features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may include only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from prior art.

[0044] In particular, all the variants and embodiments described can be combined with each other if there are no technical obstacles to this combination.

[0045] In the figures, elements common to several figures retain the same reference.

[0046] 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 conforming to the first aspect of the invention is intended to be mounted.

[0047] More specifically, the transverse axis Y is understood as a direction taken between one side of the motor vehicle and the opposite side of the same motor vehicle. In other words, the transverse axis Y is understood along 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.

[0048] Furthermore, the longitudinal axis X extends along a direction that runs from the front to the rear or from the rear to the front of the motor vehicle. The longitudinal axis X is perpendicular to the transverse axis Y. The adjectives front, front, and rear refer to this longitudinal axis X.

[0049] Finally, the vertical axis Z is understood as being taken along an axis that extends from the wheels of the motor vehicle 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.

[0050] With reference to FIGURES 1 and 2, the invention addresses a rear body structure 1 for a motor vehicle, the rear body structure 1 comprising:

[0051] - 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;

[0052] - 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, such that an internal rebate 111 of the rear side member 11 is fixed rigidly to the corresponding rear side member 12. Each rear side member 11 thus takes the form of a prismatic beam extending along one of the lateral sides of the motor vehicle. The rear side member 11 extends along the rear side member 12 to which it is associated, bordering it externally, relative to the transverse axis Y;

[0053] - a rear crossmember 13 extending transversely between the two rear side members 12, in front of the rear axle supports, the rear crossmember 13 being fixed rigidly to the rear side members 12 by means of crossmember end fittings fixed to the lateral ends of said rear crossmember 13. The rear crossmember 13 has the shape of a prismatic beam that extends transversely of the two rear longitudinal members 12. The rear cross member 13 is fixed securely to the rear longitudinal members 12 by any means, and / or preferably by welding or bolting;

[0054] - at least one reinforcement element 14 allowing a vehicle lifting jack to be supported at a support area 141, the at least one reinforcement element 14 being fixed securely to one of the rear longitudinal members 11 and to the corresponding rear longitudinal member 12.

[0055] According to an essential feature of the invention, for each at least one reinforcing member 14, the corresponding rear longitudinal member 11 and rear longitudinal member 12 are fixed together through the same fastening member 15.

[0056] In particular, the fastening member 15 is configured to establish a simultaneous, rigid fastening, that is, together, of the rear side member 12 with the associated rear side member 11 and the associated reinforcement member 14. As can be seen in FIGURE 2, at the fastening member 15, the rear side member 12, the associated rear side member 11, and the associated reinforcement member 14 are superimposed on one another to allow for a single common fastening.

[0057] For this purpose, the rear side member 12 has a flap 121 that extends against an internal rebate 111 of the rear side member 12. Thus, the fastening member 15 is configured to securely fasten together, via a common connection, a lower portion of the rear side member 11, relative to the vertical axis Z, a lower portion of the associated reinforcement member 14, and the flap 121 of the associated rear side member 12. As can be seen in FIGURE 2, the flap 121, the rear side member 11, and the associated reinforcement member 14 are advantageously superimposed at the fastening member 15.

[0058] Preferably, the fastening member 15 is configured to establish a permanent connection between the rear side member 12, the rear side member 11, and the associated reinforcement member 14. More specifically, the fastening member 15 is configured to establish a local fusion connection between the rear side member 12, the rear side member 11, and the associated reinforcement member 14. The fastening member 15 thus includes at least one triple-thickness weld point 151, 152 through the flap 121 of the rear side member 12, the rear side member 11. 11 and associated reinforcement member 14, and preferably two weld points 151, 152 as shown in FIGURE 2. The two weld points 151, 152 are distributed along the longitudinal axis X on a lower edge of the reinforcement member 14, located opposite the flap 121 of the reinforcement member 14, at the level of an overlap zone of the rear longitudinal member 11, said flap 121 and the reinforcement member 14.

[0059] In particular, and advantageously, the fastening member 15 has a first weld point 151 located on a front part of the lower edge of the reinforcing member 14, and a second weld point 152 located at a rear part of the lower edge of the reinforcing member 14. This advantageous configuration allows the rear side member 11, the associated rear side member 12 and the associated reinforcing member 14 to be fixed together efficiently.

[0060] In particular, each reinforcing member 14 comprises a first bearing area located on the front edge and a second bearing area located on the rear edge. Both the first and second bearing areas bear against the inner rebate 111 of the corresponding rear side member 11 and opposite the flap 121 of the corresponding rear side member 12. Each bearing area forms a protrusion extending from the reinforcing member 14, creating a bearing platform against the inner rebate 111 of the opposite rear side member 12 and its flap 121. Consequently, the first weld point 151 located on the first bearing area of ​​the reinforcing member 14 allows the flap 121 of the rear side member 12, the opposite rear side member 11, and the reinforcing member 14 to be securely fastened together.Similarly, the second weld point 152 located on the second support area of ​​the reinforcement member 14 allows the flap 121 of the rear longitudinal member 12, the rear longitudinal member 11 located opposite and the said reinforcement member 14 to be fixed together securely.

[0061] The rear body structure 1 thus delimits, between each rear longitudinal 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.

[0062] Each reinforcing element 14 takes the form of a stamped sheet metal, shaped to extend between an upper and a lower edge of the longitudinal member. rear 11 to which it is associated. In the context of the present invention, the reinforcing member 14 is fixed to the rear side member 11 and at its lower edge by means of the fastening member 15. The reinforcing member 14 has a cross-section, taken perpendicular to the longitudinal axis X, in the shape of an "S". The bearing area 141 of the reinforcing member 14 has a plane that extends inclinedly to the rear side member 11, so as to facilitate the subsequent placement of a jack.

[0063] Advantageously, the fastening element 15 associated with the reinforcing element 14 is located on either side of the bearing area 141 of the reinforcing member 14. In other words, relative to the vertical axis Z, the fastening member 15 is located at the level of a lower part of the reinforcement member 14. The lower part of the reinforcement member 14 is supported against the inner rebate 111 of the associated rear longitudinal member 11.

[0064] In summary, 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.

[0065] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the various features, forms, variants, and embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. Specifically, all the variants and embodiments described above are combinable.

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 fixed integrally 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 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 (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 i

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