ELECTRIC OR HYBRID MOTOR VEHICLE WITH TRACTION BATTERY IN THE FLOOR

Abstract

A motor vehicle comprising a power supply battery for an electric traction machine (4) of this vehicle, arranged flat within the thickness of the floor of the vehicle's passenger compartment, between the outer sill members (8) of the vehicle, this battery (4) comprising, for its cooling, heat exchange plates including at least one vertical plate (28) arranged along the transverse direction of the vehicle, this vertical plate comprising on each side of the vehicle at least one reinforcing plate (40) connecting its end to a face (12) of the sill (8) facing inwards towards this vehicle, which, in the event of an external impact on the sill, transmits a force to the vertical plate (28). Figure 1

Description

Title of the invention: ELECTRIC OR HYBRID MOTOR VEHICLE WITH TRACTION BATTERY IN THE FLOOR

[0001] The present invention relates to an electric or hybrid motor vehicle equipped with a traction battery arranged in the floor.

[0002] A known type of electric vehicle, presented in particular by documents WO-Al-2020038698 and US-A1-20230014338, comprises a power supply battery for an electric traction machine composed of assembled electrochemical cells, forming a flat assembly arranged at the level of the floor of the passenger compartment of the vehicle, between the front and rear axles.

[0003] The arrangement of the traction battery flat at floor level, having a significant mass, makes it possible to use a sufficiently large space formed at the base of the passenger compartment, giving the vehicle a center of gravity which remains low. In addition, the battery arranged in a lower central part of the vehicle is better protected against external impacts in the event of an accident.

[0004] Furthermore, the battery presented by document US-A1-20230014338, comprises a thick lower plate comprising an interior volume for circulating a cooling fluid to carry out a heat exchange with this battery fixed thereon.

[0005] During an accident with an impact on the vehicle causing deformation of the battery, high stresses can be obtained on its electrochemical elements with risks of heating and ignition causing a fire.

[0006] Generally speaking, vehicle bodies have on each side rocker panels forming strong side members to protect the battery against side impacts, which must meet standardized tests, in particular for point impacts against a compact element such as a post.

[0007] In the event of a side impact on the vehicle, to limit the deformation of the battery, the type of vehicle presented above comprises on each side of this battery, in the longitudinal direction of the vehicle, a profile fixed to the battery, arranged at a small distance from the inner side of the underbody, comprising cells formed along the length which constitute a structure having lateral resistance to impacts.

[0008] For a specific external impact on the underbody of the vehicle, if it deforms this underbody sufficiently by transmitting a stress to the profile arranged behind, this profile distributes the pressure over a larger surface on the side of the battery to protect it.

[0009] However, this profile fixed to the side of the battery can cause problems in the event of transmission of forces onto this battery which deform it, and onto its electrochemical elements contained inside which can receive excessively high stresses with risks of incidents.

[0010] The present invention aims in particular to avoid these problems of the prior art.

[0011] To this end, it proposes a motor vehicle comprising a battery power supply of an electric traction machine of this vehicle, arranged flat in the thickness of the floor of the passenger compartment of the vehicle, between external side members of the underbody of the vehicle, this battery comprising for its cooling heat exchange plates comprising at least one vertical plate arranged in the transverse direction of the vehicle, this vehicle being remarkable in that the vertical plate comprises on each side of the vehicle at least one reinforcing sheet connecting its end to a face of the underbody facing the interior of this vehicle, which in the event of an external impact on the underbody transmits a force to the vertical plate.

[0012] An advantage of this motor vehicle is that in a simple and economical manner, with the addition only of reinforcing sheets fixed on one side to the inner face of the underbody and on the other side to the end of the vertical thermal plate, in the event of a point impact on the outside of the underbody, a privileged transmission of force to this thermal sheet is obtained, which is resistant. The thermal plate receiving a large part of the force coming from the deformation of the underbody, thus protects the electrochemical cells of the battery arranged on each side of this sheet.

[0013] The motor vehicle according to the invention may further comprise one or more of the following characteristics, which may be combined with each other.

[0014] Advantageously, each reinforcing sheet has in a horizontal plane a right-angled section comprising a transverse side fixed flat on the vertical plate and a longitudinal side fixed flat on the inner face of the underbody.

[0015] In this case, advantageously the transverse side of the reinforcing sheet is fixed to the vertical plate by welding or screwing.

[0016] Furthermore, advantageously the longitudinal side of the reinforcing sheet is fixed to the inner face of the underbody by welding or screwing.

[0017] Advantageously, each end of the vertical plate comprises two reinforcing sheets.

[0018] In this case, advantageously the two reinforcing sheets comprise longitudinal sides fixed flat on the inner face of the underbody, extending in two opposite directions.

[0019] Advantageously, the vehicle comprises a lower heat exchange plate arranged below the battery, comprising an end fixed to the plate vertical.

[0020] In addition, the vehicle may comprise an intermediate heat exchange plate arranged above electrochemical cells placed on the lower heat exchange plate, comprising one end fixed to the vertical plate.

[0021] Advantageously, the battery comprises electrochemical cells which, following the transverse direction of the vehicle, are arranged set back from the end edge of the vertical plate.

[0022] In particular, the battery may comprise a part arranged at the rear of the vehicle comprising the vertical plate.

[0023] The invention will be better understood and other characteristics and advantages will appear more clearly on reading the description below given by way of example, with reference to the appended drawings in which:

[0024] [Fig.l] is a bottom view of an electric vehicle according to the invention;

[0025] [Fig.2] is a side view of the battery of this vehicle showing the ends of the thermal plates without the reinforcing sheet;

[0026] [Fig.3] is a vertical sectional view of this battery along the transverse direction of the vehicle;

[0027] [Fig.4] is a perspective view of the side of the battery including the reinforcing sheet lateral; and

[0028] [Fig.5] is a horizontal sectional view along the section plane VV of the edge of the battery at the level of the vertical heat exchange plate.

[0029] Throughout the document the vertical direction is established for a vehicle placed on horizontal ground, the upper or above indications being relative to this vertical direction.

[0030] [Fig.l] shows the underside of an electric vehicle comprising between the two axles of the wheels 2 a substantially flat vehicle traction battery 4, covering the entire passenger compartment of the vehicle. The battery 4 has on each side in the transverse direction of the vehicle an edge arranged at a small distance from the inner face 12 of the rocker panel side member 8.

[0031] The vehicle undergoes standardized point side impact tests simulating the impact against a pole 10, distributed along the length of the vehicle between the front and rear wheels 2, in order to check the effects on the battery 4 to protect it and avoid problems with its electrochemical elements.

[0032] The rear part of the battery 6 comprises a vertical heat exchange plate, arranged in the transverse direction of the vehicle, the ends of which are connected by reinforcing sheets 40 to the inner face of the rocker panel side member 12.

[0033] [Fig. 2] shows heat exchange plates for cooling the electrochemical cells of the battery 4, comprising a horizontal lower plate 20 receiving from below a lower protective sheet 32, and from above a first set of electrochemical cells 22. A horizontal intermediate plate 24 placed on the first set of cells 22, receives above a second set of cells 26.

[0034] The vertical heat exchange plate 34, rigidly fixed to the two horizontal plates 20, 24, receives on the side opposite the intermediate exchange plate 24 a third set of cells 30 which is attached to it.

[0035] The outer lateral edge 34 of the vertical exchange plate 34 is fitted to the edge 36 of the intermediate plate 24, the cell assemblies 22, 26, 30 being set back from these edges. The end of the vertical exchange plate 34 has holes 38 which are offset outwards relative to the cell assembly 22, 26, 30.

[0036] Each heat exchange plate 20, 24, 28 has a thickness that is sufficiently large to form inside it a flat volume for circulation of the heat transfer fluid in order to cool the electrochemical cells, which gives them high rigidity. With these rigid heat exchange plates 20, 24, 28 fixed together, a three-dimensional structure is obtained which has significant mechanical strength, in particular to receive lateral impacts along the transverse direction of the vehicle.

[0037] Figures 3, 4 and 5 show the edge of the vertical exchange plate 28 receiving two reinforcing sheets 40 each forming in vertical view a bracket comprising a side arranged in the transverse direction 42, fixed flat on one face of this thermal plate, and a side arranged in the longitudinal direction of the vehicle 44, fixed flat on the inner face 12 of the underbody 8 by welds or screws.

[0038] The longitudinal sides 44 of the two reinforcing sheets 40 are arranged in two opposite directions, constituting on the inner face of the underbody 12 a reinforcing zone which extends in the longitudinal direction on both sides of the vertical thermal plate 28 to increase the bearing surface on this face.

[0039] The transverse sides 42 of the reinforcing sheets 40 are welded to the end of the vertical heat exchange sheet 28 to ensure a rigid mechanical connection.

[0040] A direct mechanical connection is obtained between the underbody 8 and the vertical thermal plate 28 which is rigidly fixed to the two horizontal plates 22, 24.

[0041] In the case of a lateral impact on the vehicle by a post 10, the stress F applied to the underbody 8 is transmitted by the two reinforcing sheets 40 to the vertical thermal plate 28, which in turn distributes a force F1 on the horizontal plates 20, 24. This results in crushing of the underbody 8 and deformation of the reinforcing sheets 40 which absorb energy, but a very limited deformation of the edge 34 of the vertical heat exchange sheet 28 which is part, with the other two heat exchange plates 20, 24 of a resistant structure.

[0042] The electrochemical cells of the assemblies 22, 26, 30, arranged set back from the edge 34 of the vertical exchange sheet 28, are protected and do not undergo any deformation. Protection of the battery 4 in the event of lateral impacts is obtained in a simple and effective manner, with the addition of reinforcing sheets 40 having a reduced cost.

Claims

Claims

1. Motor vehicle comprising a power supply battery for an electric traction machine (4) of this vehicle, arranged flat in the thickness of the floor of the passenger compartment of the vehicle, between external side members of the underbody (8) of the vehicle, this battery (4) comprising for its cooling heat exchange plates (20, 24, 28) comprising at least one vertical plate (28) arranged in the transverse direction of the vehicle, characterized in that the vertical plate comprises on each side of the vehicle at least one reinforcing sheet (40) connecting its end to a face (12) of the underbody (8) facing the interior of this vehicle, which in the event of an external impact on the underbody (8) transmits a force to the vertical plate (28).

2. Motor vehicle according to claim 1, characterized in that each reinforcing sheet (40) has in a horizontal plane a right-angled section comprising a transverse side (42) fixed flat on the vertical plate (28) and a longitudinal side (44) fixed flat on the inner face of the underbody (12).

3. Motor vehicle according to claim 2, characterized in that the transverse side (42) of the reinforcing sheet (40) is fixed to the vertical plate (28) by welding or screwing.

4. Motor vehicle according to claim 2 or 3, characterized in that the longitudinal side (44) of the reinforcing sheet (40) is fixed to the inner face of the underbody (12) by welding or screwing.

5. Motor vehicle according to any one of the preceding claims, characterized in that each end of the vertical plate (28) comprises two reinforcing sheets (40).

6. Motor vehicle according to claim 5, characterized in that the two reinforcing sheets (40) have longitudinal sides (44) fixed flat on the inner face of the underbody (12), extending in two opposite directions.

7. Motor vehicle according to any one of the preceding claims, characterized in that it comprises a lower heat exchange plate (20) arranged below the battery (4), comprising one end fixed to the vertical plate (28).

8. Motor vehicle according to claim 7, characterized in that it comprises an intermediate heat exchange plate (24) arranged above electrochemical cells (22) placed on the plate lower heat exchanger (20), comprising one end fixed to the vertical plate (28).

9. Motor vehicle according to any one of the preceding claims, characterized in that the battery (4) comprises electrochemical cells (22, 26, 30) which, in the transverse direction of the vehicle, are arranged set back from the end edge (34) of the vertical plate (28).

10. Motor vehicle according to any one of the preceding claims, characterized in that the battery (4) comprises a part arranged at the rear of this vehicle (6) comprising the vertical plate (28).

Images