Underbody assembly for an electric motor vehicle

Abstract

The invention relates to an underbody assembly (1) for an electric motor vehicle, the underbody assembly (1) comprising a side longitudinal member (14) forming a hollow profile that houses a longitudinal member reinforcement (12), a battery support (13) for housing an electric traction battery, the battery support (13) being rigidly attached to the longitudinal member reinforcement (12), and at least one reinforcement plate (11) positioned facing the battery support (13) and located between the longitudinal member reinforcement (12) and a lower flange (141) of the side longitudinal member (14). The reinforcement plate (11) is configured to allow the longitudinal member reinforcement (12) to be attached therethrough to the lower flange (141) of the side longitudinal member (14) on the one hand, and to the battery support (13) on the other.

Description

Description Title of the invention: Underbody assembly for an electrified motor vehicle [1] [The present invention claims priority from French application 2308470 filed on August 4, 2023, the content of which (text, drawings, and claims) is incorporated herein by reference. The technical context of the present invention is that of electrified motor vehicles, and in particular devices for reinforcing the physical integrity of the underbody components of such electrified motor vehicles. More specifically, the invention relates to an underbody assembly for an electrified motor vehicle.] [2] In the state of the art, chassis of electrified motor vehicles are known comprising a battery support housed under a passenger compartment floor and fixedly attached to side rails which extend from the front and rear of the motor vehicle on either side of the passenger compartment. Such side rails make it possible to provide the expected rigidity to the chassis. In a known manner, the battery supports comprise peripheral edges which serve as fixing lugs for the side rails. Thus, the known battery supports are fixedly attached by means of screws and / or rivets which extend through the peripheral edge and across the side rail. [3] As is known, each side spar takes the form of a hollow body within which a spar reinforcement extends. The spar reinforcement thus forms a prismatic beam that strengthens and provides the mechanical rigidity of the side spar to which it is attached. As is known, the battery support is attached directly to the spar reinforcement since it is the latter that provides the required mechanical rigidity. [4] However, in such a known assembly, the battery holder is fixed - via its peripheral edge - through the hollow body, which leads to rigidity defects during side impact tests. Of course, this situation is not desired. [5] The object of the present invention is to propose a new underbody assembly in order to address at least a large part of the preceding problems and to further lead to other advantages. [6] Another aim of the invention is to reinforce the rigidity of the base. [7] Another object of the invention is to improve the fixing of a battery support on the side member reinforcement as well as the fixing of the side member reinforcement on the side member itself. [8] Another object of the invention is to facilitate the fixing of the battery support on the side member reinforcement. [9] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with an underbody assembly for an electrified motor vehicle, the underbody assembly comprising:

[0010] - a lateral side member forming a hollow profile housing a side member reinforcement;

[0011] - a battery support for housing an electric traction battery, the battery support being securely fixed to the side member reinforcement;

[0012] - at least one reinforcement plate located opposite the battery support and housed between the side member reinforcement and a lower wing of the side member.

[0013] In the context of the present invention, an electrified motor vehicle may be of the type of an electric vehicle towed exclusively by an electric machine powered by an electric traction battery, or of the type of a hybrid motor vehicle comprising both the electric machine powered by the electric traction battery and associated with another propulsion system, such as a heat engine, to propel the motor vehicle. Among hybrid motor vehicles, a distinction is made between plug-in hybrid vehicles for which the electric traction battery can be recharged by connection to an external energy source, and non-plug-in hybrid vehicles, i.e. which are not equipped for such recharging of the electric traction battery on an external electrical network.

[0014] Generally speaking, a powertrain of such an electrified motor vehicle is rotated by an electric machine, electrically powered by an 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 traction chain and allowing the electric traction battery to be recharged.

[0015] In the context of the present invention, the electric traction battery is a high-voltage electric battery making it possible to generate 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 the powertrain of the motor vehicle.

[0016] In the context of the present invention, the lateral side member forms a prismatic bearing surface which extends relative to a longitudinal axis of the motor vehicle, at each lateral edge of said motor vehicle. The lateral side members form structural elements of the motor vehicle to which other parts of the motor vehicle are attached. The lateral 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. In the context of the present invention, the lateral side member forms a hollow prismatic bearing surface housing the side member reinforcement

[0017] In the context of the present invention, the lower wing of the side spar forms a lower edge of said side spar, delimiting and closing the hollow body relative to a vertical axis and downwards. The lower wing forms a folded edge of the side spar. In other words, the lower wing forms a lower flap of the side spar.

[0018] In the context of the present invention, the side member reinforcement is housed in the side member. The side member reinforcement forms a prismatic span which extends relative to the longitudinal axis of the motor vehicle, in the hollow body formed by the side member with which it is associated. The side member reinforcement forms a complementary structural element of the side member. The side member reinforcement makes it possible to increase the rigidity of the side member.

[0019] In the context of the present invention, the battery holder forms a housing for the electric traction battery. The battery holder is housed on the floor of the passenger compartment of the motor vehicle and fixed securely to the side rails, by means of the reinforcement plate.

[0020] In the context of the present invention, the reinforcement plate forms an interface part housed in the side spar, between the lower wing and the spar reinforcement.

[0021] Thus, the reinforcement plate fills the empty space that existed in the side spar, between its lower wing and the spar reinforcement. This advantageous configuration makes it possible to reinforce the attachment of the battery support and to reinforce the rigidity of the connection between, on the one hand, the spar reinforcement and, on the other hand, the side spar and the battery support.

[0022] The base assembly 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:

[0023] - the reinforcement plate comprises a base and at least one stud extending projecting from the base, such that a bearing face of the base and a free face of the at least one stud respectively bear against a lower face of the spar reinforcement and an inner face of the lower wing of the lateral spar. In particular, the reinforcement plate comprises two studs located at a longitudinal end of the reinforcement plate. The two reinforcement studs are located at a distance from each other, relative to the longitudinal axis of extension of the reinforcement plate, such that there is a groove between the first stud and the second stud. This advantageous configuration makes it easier to mount and fix the reinforcement plate on the spar reinforcement and to mount and fix the battery support on the spar reinforcement through said reinforcement plate;

[0024] - the base of the reinforcement plate has a general rectangular shape;

[0025] - each at least one plot has a general conformation of prismatic shape. In particular, each at least one plot has a square or rectangular section;

[0026] - the reinforcing plate comprises means for fixing to the spar reinforcement. In particular, the fixing means comprise at least one rivet extending through at least one opening of the reinforcing plate and a complementary hole provided on the spar reinforcement. Preferably, the fixing means comprise (i) a first rivet extending through a first opening of the reinforcing plate located near a first longitudinal end of said reinforcing plate, and a first complementary hole provided on the spar reinforcement and located opposite the first opening, and (ii) a second rivet extending through a second opening of the reinforcing plate located near a second longitudinal end of said reinforcing plate, and a second complementary hole provided on the spar reinforcement and located opposite the second opening;

[0027] - each at least one stud comprises a tapped hole passing through said stud in a secant manner, and preferably perpendicular, to the base of the reinforcement plate. This configuration makes it possible to authorize the assembly of the reinforcement plate on the side member reinforcement and / or the battery support on said reinforcement plate. In particular, the reinforcement plate comprises (i) a first fixing stud comprising a first tapped hole collaborating with a fixing screw engaged through a first passage hole provided on the lower wing of the side member and through the side member reinforcement, and (ii) a second fixing stud comprising a second tapped hole collaborating with a fixing screw engaged through a second passage hole provided on the lower wing of the side member, a second fixing hole provided on a peripheral edge of the battery support and through the side member reinforcement;

[0028] - the battery support comprises a peripheral rim along which at least one second fixing hole is provided allowing the engagement of a battery support fixing screw in the side member reinforcement and through the reinforcement plate, the peripheral rim comprising a peripheral clearance at each at least one second fixing hole in order to receive a head of the fixing screw.

[0029] According to a second aspect of the invention, there is provided an electrified motor vehicle comprising an underbody assembly in accordance with the first aspect of the invention or according to any of its improvements.

[0030] Various embodiments of the invention are provided, incorporating, in all their possible combinations, the various optional features set out herein.

[0031] 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:

[0032] [Fig.1] illustrates a three-dimensional view of an example of the realization of a reinforcement plate for a substructure assembly according to the invention;

[0033] [Fig.2] illustrates an example of the realization of a base assembly equipped with the reinforcement plate illustrated in FIGURE 1;

[0034] [Fig.3] illustrates a cross-sectional and detailed view of the entire substructure shown in FIGURE 2;

[0035] [Fig.4] illustrates a longitudinal and detailed cross-sectional view of the entire substructure shown in FIGURE 2.

[0036] 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.

[0037] In particular, all the variants and embodiments described can be combined with each other if there is no technical obstacle to this combination.

[0038] In the figures, elements common to several figures retain the same reference.

[0039] With reference to FIGURE 2, the invention relates to a base assembly 1 for an electrified motor vehicle, the base assembly 1 comprising:

[0040] - a lateral spar 14 forming a hollow profile housing a spar reinforcement 12;

[0041] - a battery support 13 for housing an electric traction battery, the battery support 13 being securely fixed to the side member reinforcement 12;

[0042] - at least one reinforcement plate 11 - not visible in FIGURE 1 - located opposite the battery support 13 and housed between the spar reinforcement 12 and a lower wing 141 of the lateral spar 14.

[0043] The battery support 13 extends beneath a floor 10 of the motor vehicle, between the two side members 14 that border it. The battery support 13 is configured to house an electric traction battery. The battery support 13 is rigidly fixed to the side member reinforcement 12 at the lateral sides of the floor 10. To this end, the battery support 13 has a peripheral rim 131 that forms a platform for bearing and securing against the side member 14 and its side member reinforcement 12. In other words, the battery support 13 has a transverse profile in the shape of a "T", as partially visible in FIGURE 3.

[0044] With reference to FIGURE 3, the side rail 14 forms a hollow body inside which the side rail reinforcement 12 extends. The side rail 14 has a transverse profile in L, U or circular or rectangular or square.

[0045] The spar reinforcement 12 forms a prismatic span - here in a honeycomb structure - which reinforces the rigidity of the lateral spar 14 in which it is inserted. The spar reinforcement 12 extends between the lower wing 141 and an upper wing of the lateral spar 14.

[0046] The lower wing 141 of the lateral spar 14 forms a lower edge of said lateral spar 14, delimiting the hollow body relative to a vertical axis and downwards. The lower wing 141 thus forms a folded edge of the lateral spar 14, against which the reinforcement plate 11 is intended to be supported.

[0047] The reinforcement plate 11 is described with reference to the exemplary embodiment illustrated in FIGURE 1.

[0048] The plate has a generally rectangular, or even parallelepipedal, shape. It extends along an elongation axis so that it can be introduced into the lateral spar 14, between the spar reinforcement 12 and the lower wing 141 of said lateral spar 14.

[0049] The reinforcement plate 11 comprises a base 111 and at least one stud 112, 112A, 112B extending projecting from the base 111, such that a bearing face 116 of the base 111 and a free face 117 of the at least one stud 112, 112A, 112B respectively bear against a lower face of the spar reinforcement 12 and an inner face of the lower wing 141 of the lateral spar 14.

[0050] In the embodiment illustrated in FIGURE 1, the reinforcement plate 11 comprises a first pad 112A and a second pad 112B 112, 112A, 112B, the two pads 112, 112A, 112B being located at a longitudinal end of the reinforcement plate 11. The two reinforcement pads 112, 112A, 112B are located at a distance from each other, relative to the longitudinal axis of extension of the reinforcement plate 11, so that there is a groove 115 between the first pad 112A and the second pad 112B 112, 112A, 112B.

[0051] The pads 112, 112A, 112B have a general prismatic shape. In particular, the first pad 112A and the second pad 112B each have a square section.

[0052] The first pad 112A and the second pad 112B each comprise a tapped hole 114, 114A, 114B passing through said pads 112, 112A, 112B. The tapped holes 114, 114A, 114B pass through both the base 111 and the corresponding pads 112, 112A, 112B of the reinforcement plate 11. In the exemplary embodiment illustrated in FIGURE 1, the reinforcement plate 11 comprises:

[0053] - a first fixing stud 112A comprising a first tapped hole 114A collaborating with a fixing screw 15 engaged through a first passage hole provided on the lower wing 141 of the lateral spar 14 and through the spar reinforcement 12, and

[0054] - a second fixing stud 112B comprising a second tapped hole 114B collaborating with a fixing screw 15 engaged through a second hole of passage provided on the lower wing 141 of the lateral spar 14, of a second fixing hole provided on a peripheral edge 131 of the battery support 13 and through the spar reinforcement 12.

[0055] The sectional views in FIGURES 3 and 4 highlight this assembly configuration.

[0056] Of course, the lower wing 141 of the lateral spar 14 comprises at least one passage hole in a number equivalent to the corresponding tapped holes 114, 114A, 114B arranged on the reinforcement plate 11 and according to the number of reinforcement plates 11 installed on the underbody assembly 1 according to the invention.

[0057] For this purpose, it is advantageous for the underbody assembly 1 to comprise at least two reinforcing plates 11 distributed longitudinally along each lateral side member 14, in order to better support the mechanical forces associated with the fixing of the battery support 13 or the mechanical stresses appearing during a lateral impact. In this case, each lateral side member 14 comprises several through holes, in a number equivalent to the geometry of the reinforcing plate 11.

[0058] The reinforcement plate 11 further comprises means for fixing to the spar reinforcement 12 which comprise at least one rivet extending through at least one opening 113, 113A, 113B of the reinforcement plate 11 and a complementary hole provided on the spar reinforcement 12. In the exemplary embodiment illustrated in FIGURE 1, the fixing means comprise:

[0059] - a first rivet extending through a first opening 113A of the reinforcement plate 11 located near a first longitudinal end of said reinforcement plate 11, and a first complementary hole provided on the spar reinforcement 12 and located opposite the first opening 113A, and

[0060] - a second rivet extending through a second opening 113B of the reinforcement plate 11 located near a second longitudinal end of said reinforcement plate 11, and a second complementary hole provided on the spar reinforcement 12 and located opposite the second opening 113B.

[0061] The sectional views in FIGURES 3 and 4 highlight this assembly configuration.

[0062] As seen in FIGURE 3, the peripheral edge 131 of the battery support 13 along which the second fixing hole is arranged allowing the engagement of a fixing screw 15 of the battery support 13 in the side member reinforcement 12 and through the reinforcement plate 11, has a peripheral clearance 132 at each second fixing hole in order to receive a head of the fixing screw 15.

[0063] In summary, the invention relates to a base assembly 1 for an electrified motor vehicle, the base assembly 1 comprising (i) a lateral side member 14 forming a hollow profile housing a side member reinforcement 12, (ii) a battery support 13 for housing an electric traction battery, the battery support 13 being fixed integrally to the side member reinforcement 12, and (iii) at least one reinforcement plate 11 located opposite the battery support. 13 and housed between the spar reinforcement 12 and a lower wing 141 of the lateral spar 14. The reinforcement plate 11 is configured to allow fixing through it of the spar reinforcement 12 on the lower wing 141 of the lateral spar 14 on the one hand, and, on the other hand, battery support 13.

[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. Underbody assembly (1) for an electrified motor vehicle, the underbody assembly (1) comprising: - a lateral spar (14) forming a hollow profile housing a spar reinforcement (12); - a battery support (13) for housing an electric traction battery, the battery support (13) being securely fixed to the side member reinforcement (12); characterized in that the underbody assembly (1) comprises at least one reinforcement plate (11) located opposite the battery support (13) and housed between the side member reinforcement (12) and a lower wing (141) of the side member (14).

2. Underbody assembly (1) according to the preceding claim, wherein the reinforcing plate (11) comprises a base (111) and at least one stud (112, 112A, 112B) extending projecting from the base (111), such that a bearing face (116) of the base (111) and a free face (117) of the at least one stud (112, 112A, 112B) respectively bear against a lower face of the side member reinforcement (12) and an inner face of the lower wing (141) of the side member (14).

3. Base assembly (1) according to the preceding claim, in which the base (111) of the reinforcement plate (11) has a general rectangular shape.

4. Base assembly (1) according to any one of claims 2 or 3, in which each at least one stud (112, 112A, 112B) has a general conformation of prismatic shape.

5. Underbody assembly (1) according to any one of the preceding claims, in which fixing means comprise at least one rivet extending through at least one opening (113, 113A, 113B) of the reinforcement plate (11) and a complementary hole provided on the side member reinforcement (12).

6. A base assembly (1) according to any preceding claim taken in combination with claim 2, in which each at least one stud (112, 112A, 112B) comprises a tapped hole (114, 114A, 114B) passing through said stud (112, 112A, 112B) in a secant manner, and preferably perpendicular, to the base (111) of the reinforcement plate (11).

7. Underbody assembly (1) according to any one of the preceding claims, in which the battery support (13) comprises a peripheral rim (131) along which at least one second fixing hole is arranged allowing the engagement of a fixing screw (15) of the battery support (13) in the side member reinforcement (12) and through the reinforcement plate (11), the peripheral rim (131) comprising a peripheral clearance (132) at each at least one second fixing hole in order to receive a head of the fixing screw (15).

8. Motor vehicle comprising an underbody assembly (1) according to any one of the preceding claims.

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