Battery pack casing for electric motor vehicles

Abstract

The invention relates to a battery pack housing intended to be fixedly installed under the body of a motor vehicle, comprising a hollow main body (210), open at the top, comprising a lower bottom wall (211) and a peripheral side band (212) together defining an internal volume, said main body also comprising a mounting collar (213) projecting transversely from the external side from and along the upper perimeter of said band and having a multitude of holes spaced from each other along its perimeter so as to allow the battery pack to be fixed to said body using screws (V); said body further comprising reinforcing metal plates (220) affixed against the lower face of the corner areas of said mounting collar, whose profile they follow, and each having several orifices superimposed on said holes present on said corresponding corner area.Figure to be published with the abbreviation: Fig. 2.

Description

Title of the invention: Housing for battery pack of electric motor vehicle Technical field

[0001] The present invention relates to electrically powered motor vehicles equipped with a propulsion battery pack. It relates in particular to a housing for such a battery pack. Previous technique

[0002] The propulsion battery of an electric motor vehicle comprises at least one battery module comprising several electrochemical cells capable of generating current by chemical reaction (these cells being for example of the Li-ion, Ni-Mh, or Ni-Cd type).

[0003] When such a battery comprises several modules, they are grouped in a casing to form a battery pack more commonly referred to by the English expression "battery pack" and also containing a mounting interface, electrical and fluid connection connectors, as well as electrical or electronic means for the management of electrical energy of these modules.

[0004] Such a battery pack can be arranged inside the motor vehicle by covering the passenger compartment floor with the sheet metal underbody of the vehicle, extending longitudinally between the front apron and the trunk floor, and transversely between two side rails.

[0005] However, the main drawback of such an installation is that it significantly reduces the vehicle's habitability.

[0006] In order to remedy this problem, it is therefore also known to install the battery pack under the passenger compartment floor of the body underbody of this vehicle.

[0007] Generally rectangular in shape, the housing of such an underfloor battery pack in the passenger compartment conventionally comprises at least one substantially horizontal bottom wall and a peripheral side band together defining an internal volume containing in particular the battery modules.

[0008] In order to ensure that the battery pack is held against the floor of the vehicle's passenger compartment, the casing conventionally includes a mounting collar projecting transversely on the external side from and along the upper perimeter of the peripheral side band and designed to fit the profile of the body underbody.

[0009] This fixing collar has a multitude of holes spaced apart along its perimeter so as to allow the battery pack to be fixed by screwing it to the chassis base via nuts welded to this base.

[0010] During the vehicle's driving phases, road irregularities as well as strong accelerations and decelerations generate significant torsional forces on certain elements of the body underbody which deform slightly.

[0011] This deformation also causes deformation of the battery block housing fixing collar, mainly at its four corner areas, which generates very significant stresses on the screws located in these areas, which can cause them to loosen and / or become deformed (such deformation could then prevent the battery block from being disassembled after-sales to, for example, change a battery module or an electronic box). Description of the invention

[0012] The present invention aims to improve the situation.

[0013] It proposes for this purpose a battery pack housing intended to be fixedly installed under the body of a motor vehicle, comprising a main hollow body of overall rectangular parallelepiped shape, open at the top, comprising a lower bottom wall and a peripheral side band defining together an internal volume intended to house in particular several battery modules, said main body also comprising a mounting collar projecting transversely from the external side from and along the upper perimeter of said peripheral side band and having a multitude of holes spaced from each other along its perimeter so as to allow the battery pack to be fixed to said body of the vehicle using screws; characterized in that it further comprises reinforcing metal plates affixed against the underside of the corner areas of said attachment collar, which they follow the profile of, and each having several orifices superimposed on said holes present on said corresponding corner area so as to allow the insertion of said screws through these holes.

[0014] The addition of these reinforcement plates makes it possible to ensure better rigidity of the corner areas of the housing, so as to reduce the stresses suffered by the screws ensuring the fixing of this housing at the level of these corner areas and thus to limit the risks of loosening and / or deformation of these screws.

[0015] According to preferred characteristics of said housing according to the invention: - said reinforcement plates are each fixed by several electrical welding points against the underside of a corresponding corner area of ​​said attachment collar; - said casing comprises two front reinforcement plates affixed against the underside of the two front corner areas of said attachment collar and each presenting a convex curved profile that matches that of the corresponding front corner area of ​​this attachment collar; - said casing comprises two said rear reinforcement plates affixed against the underside of the two rear corner areas of said attachment collar and each having a notched profile in the shape of a serpentine consisting of two convex curved end portions extending on either side of a central concave curved portion; - the two front corner zones and / or the two rear corner zones of said attachment collar are symmetrically identical with respect to the median vertical longitudinal plane of said main body; - said reinforcement plates are made by cutting from a sheet of metal sheet having a thickness greater than or equal to 1.5 millimeters; - said thickness is less than or equal to 2.5 millimeters; and / or - said reinforcing plates have a width of at least 20 millimeters; and / or - said width is less than or equal to 25 millimeters.

[0016] The invention also relates in a second aspect to a set of underbody components for an electric motor vehicle, comprising a body base and a battery pack fixedly installed under said base and comprising such a casing. Brief description of the drawings

[0017] The description of the invention will now be continued by a detailed description of an exemplary embodiment, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.1] represents a perspective view from below of a set of underbody parts of an electric motor vehicle comprising a body subframe and a battery pack with a casing according to the invention fixed under this subframe; - [Fig.2] is an enlargement of one of the front corner areas of the rocker panel assembly of [Fig.1]; - [Fig.3] represents a perspective view of one of the front reinforcement plates included in the casing according to the invention; - [Fig.4] is an enlargement of one of the rear corner areas of the rocker panel assembly in [Fig.1]; and - [Fig.5] represents a perspective view of one of the rear reinforcement plates included in the casing according to the invention. Description of the implementation methods

[0018] Fig. 1 represents a perspective view from below of a set of rocker panels 1 of a motor vehicle comprising an electric propulsion machine.

[0019] An orthogonal frame XYZ comprising three axes perpendicular in pairs is defined with respect to this set of rocker panels 1, namely: - an X-axis, defining a longitudinal, horizontal direction, parallel to the ground and coinciding with the general direction of movement of the vehicle - a Y-axis, defining a transverse, horizontal direction, also parallel to the ground, which, together with the X-axis, defines a horizontal XY plane, and - a Z axis, defining a vertical direction, perpendicular to the ground as well as to the horizontal XY plane.

[0020] In the remainder of the description and with reference to the frame defined above, the terms "longitudinal" or "longitudinally" shall refer to a direction parallel to the X axis, the terms "transverse" or "transversely" shall refer to a direction parallel to the Y axis, and the terms "vertical" or "vertically" shall refer to a direction parallel to the Z axis.

[0021] Furthermore, and by convention, the terms "lower," "upper," "front," and "rear" shall be understood in relation to the overall orientation of the vehicle. The terms "lower" and "low" shall indicate a closer proximity to the ground in the vertical direction than the terms "upper" or "high." The term "front" shall indicate a forward-facing position of a vehicle in the horizontal direction, and the term "rear" shall indicate a rear-facing position of a vehicle in the same horizontal direction.

[0022] The terms "external" and "internal" will be used to define the relative position of an element with reference to the vehicle's median vertical longitudinal plane. The element closest to this plane will thus be described as internal, as opposed to the other element further from this same plane, which will be described as external.

[0023] Finally, the use of the term "substantially" will indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining within the scope of the invention. For example, "substantially horizontal" will indicate that a deviation of approximately 10° to 15° from a strictly horizontal orientation is permitted within the scope of the invention.

[0024] With reference to this [Fig.1], the lower body assembly 1 comprises a sheet metal body underbody 100, including a passenger compartment floor 110 extending longitudinally between a front apron 120 and a trunk floor 130, and transversely between two side rails 140.

[0025] This lower body assembly 1 also includes a battery pack B extending along a substantially horizontal average plane and located under the passenger compartment floor 110 of the body subframe 100.

[0026] This battery block B is provided with a casing 200 comprising a main hollow body 210 of overall rectangular parallelepiped shape, open on the top, comprising a substantially horizontal bottom wall 211 and a peripheral side band 212 together defining an internal volume intended to house several non-visible battery modules each comprising several electrochemical cells capable of generating current by chemical reaction.

[0027] Advantageously produced by stamping from a single sheet of metal, the main body 210 of this housing 200 can also house other elements not shown, such as a mounting interface, electrical and fluid connection connectors, and / or electrical or electronic means for the electrical energy management of these modules.

[0028] Still with reference to [Fig.1], the lower body assembly 1 also includes a rear axle with a deformable crossmember 300 mounted on the body underbody 100 at the rear of the battery pack 200.

[0029] This rear axle 300 comprises two wheels 310 connected to each other by a cross member 320 located under the body subframe 100 and from which two lateral suspension arms 330 originate, extending substantially longitudinally near the two lateral edges of the body subframe 100.

[0030] As can be seen more clearly in [Fig.4], the front end of each longitudinal suspension arm 330 includes a ring 331 receiving an elastically deformable articulation block 332 through which a metal clevis 333 passes, the two lateral ends of which are fixed by screwing to a corresponding rear lateral end area of ​​the passenger compartment floor 110 of this body subframe 100, to achieve an elastic articulation filtering vibrations.

[0031] In order to secure it against the passenger compartment floor 110 of the vehicle, the main body 210 of the housing 200 also includes a fastening collar 213 projecting transversely on the external side from and along the upper circumference of the peripheral side band 212 and designed to fit the body underbody 100.

[0032] This attachment collar 213 has a multitude of holes (not visible in the figures) spaced apart along its perimeter so as to allow the battery pack B to be fixed by means of screws V to the chassis base 100 via nuts not visible welded to this base 100.

[0033] According to the invention, and as can be clearly seen in Figures 2 and 4, the housing 200 also comprises reinforcing metal plates 220, 230 affixed against the underside of the corner areas of the attachment collar 213 whose profile they follow, namely: - two front reinforcement plates 220 affixed against the underside of the two front corner areas of this attachment collar 213; and - two rear reinforcement plates 230 affixed against the underside of the two rear corner areas of this attachment collar 213.

[0034] With reference to figures 2 and 3, the front reinforcement plates 220 each have a convex curved profile following that of the corresponding front corner area of ​​this attachment collar 213.

[0035] With reference to Figures 4 and 5, the rear reinforcement plates 230 each have a serpentine-shaped notched profile consisting of two convex end-curved portions 230B, 230C extending on either side of a central concave curved portion 230A. It will be noted that this notched profile of the rear corner areas and the rear reinforcement plates 230 is due to the presence of the metal brackets 333 of the rear axle 300 screwed to the two rear lateral end areas of the passenger compartment floor 110.

[0036] Each fixed by several electrical weld points P against the underside of a corresponding corner area of ​​the attachment collar 213, the reinforcing plates 220, 230 are made by cutting from a sheet of metal, preferably steel, advantageously with a thickness greater than or equal to 1.5 millimeters. This thickness will also preferably be less than or equal to 2.5 millimeters so as to limit the increase in mass of the housing 200.

[0037] Each reinforcement plate 220, 230 has several holes 221, 231 (visible in figures 3 and 5) overlapping the holes present on the corresponding corner area of ​​the attachment collar 213, so as to allow the insertion of the fixing screws V through these holes.

[0038] In order that the heads of the fixing screws V passing through the corner areas of the attachment collar 213 rest entirely against the reinforcement plates 220, 230 so as to ensure an optimum level of clamping, these reinforcement plates 220, 230 advantageously have a width of at least 20 millimeters.

[0039] This width will also preferably be less than or equal to 25 millimeters so as to limit the increase in mass of the housing 200.

[0040] The two front corner areas of the attachment collar 213 are advantageously symmetrically identical with respect to the median vertical longitudinal plane of the main body 210, so as to allow the use of the same part reference for the two front reinforcement plates 220 (the latter being welded by one or the other of their face against the corresponding front corner area of ​​the attachment collar 213 depending on the left or right lateral arrangement of this corner area).

[0041] Similarly, the two rear corner areas of the attachment collar 213 are advantageously symmetrically identical with respect to the median vertical longitudinal plane of the housing 200, so as to allow the use of the same part reference for the two rear reinforcement plates 230 (the latter being welded by one or the other of their face against the corresponding rear corner area of ​​the attachment collar 213 depending on the left or right lateral arrangement of this corner area).

[0042] According to alternative embodiments not shown, the shape and / or number of the reinforcement plates may differ. The rear reinforcement plates 230 could thus, for example, be divided into several separate plates.

Claims

Demands

1. Housing (200) for a battery pack (B) intended to be fixedly installed under the body underbody (100) of a motor vehicle, comprising a hollow main body (210) of a generally rectangular parallelepiped shape, open at the top, comprising a bottom lower wall (211) and a peripheral side band (212) together defining an internal volume intended to house in particular several battery modules, said main body (210) also comprising a fastening collar (213) projecting transversely from the external side from and along the upper perimeter of said peripheral side band (212) and having a multitude of holes spaced from each other along its perimeter so as to allow the battery pack (B) to be fixed to said body underbody (100) by means of screws (V);characterized in that it further comprises reinforcing metal plates (220, 230) affixed against the underside of the corner areas of said attachment collar (213), whose profile they follow, and each having several holes (221, 231) superimposed on said holes present on said corresponding corner area so as to allow the insertion of said screws (V) through these holes.;

2. Carter (200) according to claim 1, characterized in that said reinforcement plates (220, 230) are each fixed by several electrical weld points (P) against the underside of a corresponding corner area of ​​said attachment collar (213).

3. Carter (200) according to any one of claims 1 or 2, characterized in that it comprises two said front reinforcement plates (220) affixed against the underside of the two front corner areas of said attachment collar (213) and each having a convex curved profile conforming to that of the corresponding front corner area of ​​said attachment collar (213).

4. Carter (200) according to any one of claims 1 to 3, characterized in that it comprises two said rear reinforcement plates (230) affixed against the underside of the two rear corner areas of said attachment collar (213) and each having a serpentine-shaped notched profile consisting of two convex end curved portions (230B, 230C) extending on either side of a central concave curved portion (230A).

5. Carter (200) according to any one of claims 1 to 4, characterized in that the two front corner areas and / or the two rear corner areas of said attachment collar (213) are symmetrically identical with respect to the median vertical longitudinal plane of said main body (210).

6. Carter (200) according to any one of claims 1 to 5, characterized in that said reinforcement plates (220, 230) are made by cutting from a sheet of metal sheet having a thickness greater than or equal to 1.5 millimeter.

7. Carter (200) according to claim 6, characterized in that said thickness is less than or equal to 2.5 millimeters.

8. Carter (200) according to any one of claims 1 to 7, characterized in that said reinforcing plates (220, 230) have a width of at least 20 millimeters.

9. Carter (200) according to claim 8, characterized in that said width is less than or equal to 25 millimeters.

10. A body-on-frame assembly (1) for an electric motor vehicle, comprising a body-on-frame (100) and a battery pack (B) fixedly located under said body-on-frame (100) and comprising a housing according to any one of claims 1 to 9.

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