VEHICLE WITH ELECTRIC OR HYBRID MOTORIZATION

Abstract

The invention relates to a hybrid or electric type motor vehicle whose body comprises, in the lower part, at each lateral side, a longitudinal structural part such as a side member (3), the vehicle further comprising a battery pack arranged under the floor (2) between the longitudinal structural parts, said battery pack comprising a battery tray (1) and battery modules being fixed to said longitudinal structural parts, a space (E) being provided between each longitudinal structural part and the battery pack. The invention consists in that an energy absorption layer made of an elastically deformable material is arranged in said space (E) between the battery pack (1) and each longitudinal structural part. Application to reinforcement against lateral impacts of hybrid or electric vehicles. Figure 1

Description

Title of the invention: VEHICLE WITH ELECTRIC OR HYBRID MOTORIZATION

[0001] The present invention relates to a vehicle with an electric or hybrid motor comprising a battery pack under the floor of the vehicle.

[0002] The invention is mainly applicable in the field of motor vehicles, in particular electric vehicles (EV), hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV).

[0003] The traction batteries of an electric vehicle or a hybrid electric vehicle are generally electrochemical cells or batteries of the lithium-ion type which are stored in a battery tray thus constituting a battery pack which is attached to the body of the vehicle, under the floor, by screwing the tray onto the side members of the body of the vehicle. The tray thus has a bottom whose lateral ends are arranged to be fixed to the side members of the body, and projecting walls of the bottom form a frame surrounding the space for housing the battery modules. The battery pack is mounted from below, and a clearance along the Y axis of the vehicle between the frame and the side members is then necessary for its installation.

[0004] Shock resistance standards (such as 90° or 75° pole impact) are imposed with restrictions on deceleration (less than 50G) and intrusion (no contact with a battery module). It is these legitimate restrictions that reduce the volumes available for the loading of battery modules since it is above all necessary that the battery box-pack structure meets the regulations.

[0005] Although necessary for the assembly of the battery pack, this empty space created by the play is therefore a disadvantage during a side impact since this space does not allow either the absorption or the transmission of the force induced by the impact. The consequences of this non-participation in the force are then resolved by increasing the thickness of the battery pack tray to withstand the forces during the impact, which induces a loss of available space inside the pack.

[0006] In document FR-A-3078048, a protection device is described, inserted between a battery pack and a side stretcher. This device thus aims to absorb more energy during a side impact for an electric vehicle. This device consists of an arched metal force distribution element and absorption elements made of composite material, preferably of a honeycomb type cellular structure. Each arched protection element is thus screwed into place.

[0007] Although this protective device is effective, the metal arcuate protective elements involve a complex, time-consuming access mounting process. and therefore an additional cost. In addition, the mass of the vehicle is also increased by these additional metal elements.

[0008] As the autonomy of electric or hybrid vehicles is a major issue, it is important to remedy this drawback. The invention therefore aims to resolve the problem of safety during a side impact but also the available battery volume and therefore the autonomy of an electric vehicle.

[0009] The present invention therefore aims to propose a hybrid or electric type motor vehicle in which the lateral impact absorption of electric vehicles is improved while gaining available space for battery cells.

[0010] For this purpose, the invention relates to a motor vehicle of the hybrid or electric type, the body of which comprises, in the lower part, at each lateral side, a longitudinal structural part such as a side member, the vehicle further comprising a battery pack arranged under the floor between the longitudinal structural parts, said battery pack comprising a battery tray and battery modules, being fixed to said longitudinal structural parts, a space being provided between each longitudinal structural part and the battery pack, characterized in that an energy absorption layer made of an elastically deformable material is arranged in said space between the battery pack and each longitudinal structural part.

[0011] Advantageously, this layer of elastically deformable material fills the empty space between the battery pack and the structural part and thus offers an additional energy absorption capacity improving the lateral impact absorption of electric vehicles which contributes to the protection of the battery pack during a lateral impact.

[0012] The addition of an elastically deformable material such as an elastomer in the space between a longitudinal structural part and the battery pack therefore replaces an empty space with a full volume, which makes it possible to dissipate energy during a lateral impact by elastic deformation of said material.

[0013] Advantageously, more energy can then be dissipated with an unchanged thickness of the structural part / battery tray, which improves safety. In addition, volume can be gained inside the battery pack by transferring the space gained in Y (thickness of the tray frame + side member) to the inside of the battery zone.

[0014] According to a preferred embodiment, the energy absorption layer of elastically deformable material is obtained by injecting an elastically deformable material in liquid form such as an elastomer into said space. Since the elastically deformable material is an elastomer in liquid form, such as a polyurethane elastomer such as a resin, a glue, it is thus injected between the longitudinal structural part such as a side member and the battery tray. The liquid material thus injected hardens in situ and forms the layer of elastically deformable material in the space thus filled.

[0015] According to an advantageous embodiment, the material is injected into the space between the battery pack and the longitudinal structural part using at least one injection or filling channel provided in the wall of the battery tray frame extending along the side member. Similarly, an overflow channel is also provided in this wall and makes it possible to determine when the desired filling level has been reached. This space can thus be easily filled from below the vehicle, this space no longer being accessible from above.

[0016] Preferably, the battery tray comprises a bottom on which is arranged a frame, each side wall of which is intended to be opposite the longitudinal structural part comprises at least one filling channel extending from a filling orifice arranged on the bottom of the battery tray to an end orifice opening onto the face of the side wall in the space between the tray and the structural part, and allowing the injection of the material into said space.

[0017] The filling channel therefore extends in the side wall from a filling orifice provided on the bottom of the battery tray to an end orifice opening into the space opposite the side member, allowing the injection of the material into said empty space.

[0018] Preferably, it can be provided that the filling channel has several orifices between the filling orifice and the end orifice, also provided opening into the space. Advantageously, it is thus possible to accelerate the filling speed.

[0019] A side wall of the battery tray also comprises an overflow channel extending between an orifice provided on the bottom of the battery tray and a collection end orifice opening on the face of the side wall into the space and making it possible to collect the injected material when the quantity of this material injected into the space reaches a predefined height in said space. This predefined height thus makes it possible to verify that the desired quantity of material has been injected into the space to form the energy absorption layer made of elastically deformable material. The material flowing from the overflow channel allows the operator to determine either directly by viewing the material poured out of this channel or using an optical sensor, that the quantity of material injected is sufficient and that the filling of the space can be stopped.

[0020] Preferably, the filling channel and the overflow channel are similar. Thus, the battery tray can be obtained by molding, for example in aluminum or any other suitable material, and comprises both types of channels (filling / overflow) provided in each wall intended to extend along a side member. The filling and overflow channels are for example machined by drilling or can be obtained during molding

[0021] Thus, a set of channels opens with at least one filling orifice, preferably several, to fill said space, and at least one overflow channel opens onto the wall, so that, when a predefined filling level is reached, the liquid material flows into this overflow channel which allows the operator to ensure that the correct quantity of material has been injected into the space.

[0022] The invention also relates to a battery tray for a battery pack for an electric or hybrid type motor vehicle according to the invention, comprising a bottom and projecting walls of the bottom forming a frame, characterized in that the side walls of the battery tray frame intended to extend along longitudinal structural parts of a body of the vehicle have at least two channels extending from an orifice provided in the bottom to an end orifice opening onto the face of the side walls intended to be opposite said longitudinal structural parts.

[0023] The invention also relates to a method of installing a battery pack on a hybrid or electric motor vehicle according to the invention, in which the battery pack is fixed to the longitudinal structural parts of the vehicle body, with a clearance or space formed between the battery pack and the longitudinal structural parts, characterized in that said spaces are filled with a liquid elastically deformable material, to form an energy absorption layer, by in situ hardening of said elastically deformable material, between the battery tray and the longitudinal structural parts.

[0024] The invention thus makes it possible to obtain a hybrid or electric vehicle whose protection against side impacts has been reinforced.

[0025] The invention will now be described in more detail with reference to the figures which represent:

[0026] [Fig-1] a sectional view of a lateral side of a vehicle body according to the invention once the battery pack is attached;

[0027] [Fig.2] a perspective view of the lateral side of [Fig.l];

[0028] [Fig.3] a perspective and transparency view of [Fig.l];

[0029] [Fig.4] a view along section A of [Fig.3]; and

[0030] [Fig.5] a view along section B of [Fig.3], once the material has been injected.

[0031] The main subject of the invention is therefore a motor vehicle with an electric or hybrid (thermal / electric) engine in which batteries must be installed. Conventionally, a vehicle is defined by a longitudinal axis X of the vehicle extending between the rear and the front in the direction of travel of the vehicle, by a transverse axis Y extending between the lateral sides of the vehicle, orthogonal to the X axis, and a Z axis extending vertically relative to the rolling plane of the vehicle and orthogonal to the X and Y axes.

[0032] Conventionally, the battery modules M are housed under the floor 2 of the vehicle body. They are generally contained in a battery tray 1 and the battery pack (batteries + tray 1) thus formed extends under the floor 2 of the body along the Y axis of the vehicle and is fixed to the longitudinal structural parts such as the side members 3 of the body, which extend longitudinally along the lateral sides, along the X axis of the vehicle.

[0033] Each side member 3 can be very wide and belongs to the body. It is possible to add a reinforcement such as a stretcher, inside to protect the battery pack during a side impact. The floor 2, generally made of sheet metal, is welded to the two side members 3, with a sealing bead between the two, which closes the top of the battery pack.

[0034] The battery tray 1 comprises a bottom 10 or lower floor which supports the battery modules M and the internal electronics (BMU, Bus bars, etc.).

[0035] Cross members (not shown) are provided to stiffen the assembly and transmit lateral forces. Projecting walls of the bottom 10 form a protective frame for the space for receiving the battery modules M and the side walls 11 of the frame extending along the side members 3, once the battery pack is fixed, make it possible to recover the forces coming from the side members 3 in the event of a lateral impact and to transmit them to the cross members in order to prevent the intrusion of the side member 3 into the battery pack.

[0036] Thus, the battery tray 1 comprises a bottom 10 extending under the side members 3 to be fixed there, using conventional fixing parts 12, such as M10 type screws distributed over the surface of the side member 3. A sealing gasket (EPDM type) is added to make the system airtight.

[0037] In order to allow this installation of the battery pack and its fixing on the side members 3, a clearance or space E between a side wall 11 of the battery tray 1 extending along the side member 3 and the adjacent side member 3 is necessary.

[0038] As already mentioned, this space E does not allow either the absorption or the transmission of the force induced during a lateral impact.

[0039] According to the invention, it is therefore proposed to fill the empty space E thus created between the battery pack and the spar 3 by placing in this space E an energy absorption layer made of an elastically deformable material, thus creating a solid volume in the form of an elastically deformable layer 4 which makes it possible to dissipate the energy during an impact by elastic deformation thereof.

[0040] This layer 4 is obtained by placing in this space E a filling material which thus makes it possible to produce an energy absorption layer 4 of which a face is supported against the side member 3 and the other face is supported against one face of the side wall 11 of the battery pack.

[0041] This layer 4 is obtained by the injection of an elastically deformable material such as an elastomer, a polyurethane polymer resin for example.

[0042] This elastomer may in particular consist of a polyurethane resin or glue. Such a product is in liquid form and can thus be easily injected into the clearance or space E existing between the lateral side member 3 and the battery pack, once the latter is fixed to the side members 3.

[0043] To do this, as it is not possible to fill the empty space E from above due to the presence of the floor 2, the bottom 10 and the frame of the battery tray 1 supporting the battery modules M comprise two types of channels 5, 6 on each side wall 11 opposite a side member 3.

[0044] The battery tray 1 consisting of the bottom 10 and the frame is molded in a single piece, for example in aluminum and, in order to carry out the injection of the material, this tray 1 is then machined for example by drilling to create the two types of channels 5, 6. It is also possible to provide that the channels 5, 6 are produced by molding.

[0045] A first type of channel 5 called filling or injection, allows the injection of the material to fill the empty space E using an injection nozzle through the filling channel 5. In order to cover the entire empty volume to be filled, several filling channels 5 are provided, for example five on each side of the battery tray 1.

[0046] To determine when the glue (or resin) has reached the desired filling level in space E, overflow channels 6 similar to the filling channels are provided in the frame of the battery tray 1.

[0047] The second type of channel 6, called overflow, thus makes it possible to ensure that the correct quantity of material has been injected into said space E.

[0048] The filling channel 5 or the overflow channel 6 extends from an orifice provided in the bottom 10 at the level of the side wall 11 and opens through an end orifice on the face of the wall 11 at the level of the space E. Preferably, the filling channel 5 has other orifices 51 opening into the space E for faster filling.

[0049] This filling being done from the bottom 10, therefore blindly, the overflow channel 6 thus makes it possible to visualize the filling level when the injected liquid overflows and flows from this overflow channel 6.

[0050] The filling channel 5 thus makes it possible to fill the empty space E with the elastomer material such as a polyurethane resin, which is initially in liquid form and then hardens once conveyed into the space E.

[0051] When the material reaches a certain predefined height in the space E, the material can then overflow into the collection orifice 61 of the overflow channel 6, which allows an operator to directly view this overflow and determine that the quantity of material filling the space E is sufficient to form the desired energy absorption layer 4 and thus stop the filling operation. Each filling channel 5 is then closed. The material such as the glue is allowed to harden and thus forms the absorbent junction between the body (side member) and the battery tray 1.

[0052] Overflow can also be detected by an optical sensor which then warns the operator.

Claims

Claims

1. A hybrid or electric motor vehicle whose body comprises, in the lower part, at each lateral side, a longitudinal structural part such as a side member (3), the vehicle further comprising a battery pack arranged under the floor (2) between the longitudinal structural parts, said battery pack comprising a battery tray (1) and battery modules (M) being fixed to said longitudinal structural parts, a space (E) being provided between each longitudinal structural part and the battery pack, characterized in that an energy absorption layer made of an elastically deformable material (4) is arranged in said space (E) between the battery pack (1) and each longitudinal structural part, the energy absorption layer (4) made of elastically deformable material being obtained by injecting into the space (E) an elastically deformable material in liquid form such as a polyurethane resin,preferably a polyurethane glue, the battery tray (1) comprising a bottom (10) on which is arranged a frame, each side wall (11) of which facing the longitudinal structural part (3) comprises at least one filling channel (5) extending from a filling orifice arranged on the bottom of the battery tray (1) to an end orifice opening on the face of the side wall (11) in the space (E) and allowing the injection of the material into said space (E).,

2. Vehicle according to claim 1, characterized in that the filling channel (5) has several orifices (51) between the filling orifice and the end orifice, also provided opening into the space (E).

3. Motor vehicle according to claim 1 and 2, characterized in that each side wall (11) comprises an overflow channel (6) extending between an orifice provided on the bottom of the battery tray (1) and a collection orifice (61) opening onto the face of the side wall (11) in the space (E) and making it possible to collect the injected material when the quantity of this material injected into the space (E) reaches a predefined height in said space (E).

4. Motor vehicle according to one of claims 1 to 3, characterized in that the battery tray (1) is made of aluminum, the filling (5) and overflow (6) channels being machined by drilling.

5. Motor vehicle according to one of claims 1 to 3, characterized in that the battery tray (1) is cast in aluminum, the filling (5) and overflow (6) channels being obtained during casting.

6. Battery box (1) for a battery pack for an electric or hybrid motor vehicle according to one of claims 1 to 5, comprising a bottom (10) and projecting walls of the bottom forming a frame, characterized in that the side walls (11) of the battery box frame intended to extend along longitudinal structural parts of a body of the vehicle have at least two channels (5, 6) extending from an orifice provided in the bottom to an end orifice opening onto the face of the side walls (11) intended to be opposite said longitudinal structural parts.

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