MOTOR VEHICLE WITH AN ELECTRIC BATTERY AND THERMAL SAFETY

Abstract

The invention relates to an electric motor vehicle (1) comprising a battery (3), and a channel (6) for guiding a flow of cooling and / or extinguishing fluid from a reservoir (60) of the vehicle (1) and / or an external supply station, to a fluid inlet (8) of the battery (3) or of a casing (7) enclosing the battery (3), which inlet (8) comprises a safety capsule (10) that closes it when the fluid pressure in the channel (6) is below a predetermined pressure, and is arranged to rupture and allow the passage of this fluid when the fluid pressure in the channel (6) is above this predetermined pressure. This capsule (10) advantageously comprises a deformable lid (11) that deforms under the action of a pressure above this predetermined pressure and that causes, directly or indirectly, the rupture of the lid (11). Figure 1.

Description

Title of the invention: MOTOR VEHICLE COMPRISING A BATTERY ELECTRIC WITH THERMAL SAFETY

[0001] The invention relates to an electric or hybrid motor vehicle comprising at least one battery for storing electrical energy, and a body comprising at least one channel arranged to guide a flow of cooling or / and extinguishing fluid, from at least one reservoir included in said vehicle or / and from at least one external supply station, to at least one fluid inlet included in said at least one battery, or / and included in at least one casing enclosing said at least one battery and included in said vehicle.

[0002] The invention relates to the field of batteries for electric and hybrid vehicles.

[0003] The invention also relates to the field of safety of electric or hybrid motor vehicles, and more particularly the field of prevention, limitation, or extinction of fires in these vehicles, and in particular disasters linked to thermal runaway of batteries.

[0004] Prevention concerns the prevention of fire in the event of thermal runaway of current lithium-ion technology batteries, particularly following an impact.

[0005] Extinguishing also concerns the extinguishing and control of battery fires in the event of thermal runaway in all life situations (driving, charging, crash).

[0006] Today, to combat battery fires, the known solutions are not very satisfactory:

[0007] - let the vehicle burn while securing the surrounding environment;

[0008] - use a blanket to smother the fire and let the vehicle burn out;

[0009] - water the vehicle and its battery to stop the thermal propagation and attempt to secure the vehicle;

[0010] - immerse the vehicle in a container to extinguish the fire and secure the vehicle.

[0011] It is understood that these limited solutions, among those which are technically possible for a disaster which can start anywhere, generally result in the total or partial destruction of the vehicle, we are limited to ensuring the safety of the surrounding installations. They are not compatible with the presence of occupants in the vehicle, with the case of a confined environment (private garage or underground parking), generate a release of smoke which is too significant, too toxic, too dangerous, and require an extremely long intervention time.

[0012] The risk of transfer to the passenger compartment remains high.

[0013] The quantity of water or extinguishing product used to spray an entire vehicle is very large.

[0014] Securing the vehicle is difficult to guarantee, due to the remaining energy, which can lead to a new outbreak of fire.

[0015] A better method is to directly flood the overheating battery.

[0016] Another solution is to flood the battery from the inside using a thermal or mechanical fuse on the floor in the passenger compartment of the vehicle, to provide sufficient access for the jet from a fire hose. However, the disadvantages are similar to those of conventional solutions, with the addition of discomfort for some passengers in the vehicle, generally in the rear, due to large protrusions under the seats. In addition, the water circulation is forced, and not optimized.

[0017] It is noted that these solutions are generally linked to the start of a fire, that is to say a stage at which thermal runaway is difficult to reverse.

[0018] Document FR3002910 A1 describes a supporting structure for a hybrid or electric vehicle, used for extinguishing a battery fire. This structure comprises hollow bodies forming channels which are located near a compartment dedicated to the batteries. It has an external access means allowing the channels to be filled with a fluid and, on the other hand, orifices for diffusing this fluid from these channels towards the battery compartment.

[0019] Document KR102367529 B1 discloses a device for an electric vehicle for extinguishing a fire comprising a water inlet provided on the cover of a battery pack and a fire extinguishing water pipe provided outside the battery pack, one end of which is connected to the water pipe and the other end of which is connected to a fire pipe in the vehicle body.

[0020] Document JP5849692 B2 describes a conduit coming from a dedicated hatch and going to the battery pack, allowing the latter to be extinguished in the event of a fire. This conduit allows the insertion of a fire hose.

[0021] However, these solutions are not protected against a possible malicious act on this hatch and this conduit, nor against an error of interpretation and an untimely maneuver by the user of the vehicle.

[0022] On the other hand, there is no guarantee that the batteries, after thermal runaway or a disaster, remain correctly protected against possible further overheating.

[0023] The objective of the present invention is to overcome these drawbacks by proposing a motor vehicle comprising an electric traction battery with a thermal safety device, this device allowing easy access without any other mechanism than the pressure of a cooling and / or extinguishing fluid, in particular water, from outside the vehicle to the battery in order to be able to cool effectively with this fluid, stop thermal propagation and secure the battery pack, also called pack, against further thermal runaway or fire outbreak

[0024] Such a safety device according to the invention comprises a single-use safety capsule in the event of an accident or at least in the event of thermal runaway, and which comprises, more particularly, a self-piercing cover in order to control thermal propagation and secure the battery in the event of thermal runaway.

[0025] To achieve this objective, the invention proposes an electric or hybrid motor vehicle comprising at least one battery for storing electrical energy, and a body comprising at least one channel arranged to guide a flow of cooling or / and extinguishing fluid, from at least one reservoir included in said vehicle or / and from at least one external supply station, to at least one fluid inlet included in said at least one battery, or / and included in at least one casing enclosing said at least one battery and included in said vehicle.

[0026] According to the invention, said at least one fluid inlet comprises a safety capsule closing said at least one fluid inlet when the fluid pressure in said at least one channel is lower than a predetermined pressure, and which safety capsule is arranged to break and allow passage to a said cooling and / or extinguishing fluid when the fluid pressure in said at least one channel is higher than said predetermined pressure.

[0027] Thanks to the invention, access of the fluid to the battery or its container is only possible under a well-defined pressure condition, and is not possible by a malicious act committed without special equipment, nor during an incorrect maneuver. The rupture of the safety capsule according to the invention guarantees the irreversible nature of the intervention in progress to regulate the temperature of a battery and / or a battery pack; it also requires the vehicle to pass through a workshop approved by the manufacturer for reconditioning with the installation of the appropriate number of new safety capsules, and then guarantees the protection of the battery(ies) in the event of a new thermal runaway, which may, as explained above, result from an uncontrollable event such as a collision, independent of the management of the vehicle.

[0028] Advantageously, said safety capsule comprises a cover which is deformable under the action of a fluid pressure in said at least one channel greater than said predetermined pressure, from a rest position when the fluid pressure in said at least one channel is less than said predetermined pressure, to a fluid passage position when the fluid pressure in said at least one channel is greater than said predetermined pressure and causes, directly or indirectly, the irreversible tearing of said cover.

[0029] Such a cover is a low-cost safety component, the irreversible destruction of which in the event of overpressure ensures the passage of the cooling or / and extinguishing fluid, which may be a liquid or an inert gas, to the organ to be protected: battery or / and battery pack.

[0030] Advantageously, said safety capsule comprises at least one perforating element arranged to pierce said seal when the fluid pressure in said at least one channel is greater than said predetermined pressure and when said fluid pressure deforms said seal until said seal is torn, and / or said at least one perforating element passes through said seal.

[0031] This perforating element ensures the rapid destruction of the cover, and also constitutes a passive security element, with a very low manufacturing cost.

[0032] Advantageously, in conjunction with the presence of a perforating element, said cover comprises at least one rupture initiator arranged to break upon perforation of said cover by said at least one perforating element.

[0033] This arrangement ensures the speed of destruction of the cover, and its total destruction, without hindering the passage of the fluid.

[0034] Advantageously, when the fluid pressure in said at least one channel is greater than said predetermined pressure and directly or indirectly causes the irreversible tearing of said seal, said seal comprises at least one rupture initiation point which is arranged to break under the effect of a fluid pressure in said at least one channel greater than said predetermined pressure.

[0035] This configuration also ensures the complete destruction of the seal, and the passage of the fluid without any brake at the fluid inlet.

[0036] Advantageously, said cover is made of aluminum alloy, or ductile steel sheet, or composite material that melts under a pressure greater than said predetermined pressure.

[0037] It is thus possible to perfectly adapt the cover to the pressure predetermined by the manufacturer to allow access of the fluid. Shaping a cover around an axis of revolution is easy, according to well-known and economical methods. It is understood that such a cover, fairly resistant by its design, is preferably coupled with a perforating element.

[0038] Advantageously, said cover has a thickness of between 0.25 mm and 0.50 mm.

[0039] Here too, the choice of thickness is linked to the pressure predetermined by the manufacturer to allow access of the fluid.

[0040] Advantageously, said vehicle comprises at least one said envelope comprising at least one said safety capsule at the outlet of said at least one channel, said at least one envelope containing, in a chamber arranged to contain said cooling and / or extinguishing fluid, at least one said battery which itself comprises at least one said safety capsule.

[0041] It is thus possible to differentiate the access of the fluid to the interior of the casing or the battery itself.

[0042] Advantageously and more particularly, said predetermined pressure to which said at least one safety capsule of said envelope is calibrated is different from said predetermined pressure to which said at least one safety capsule that said at least one battery comprises is calibrated.

[0043] The manufacturer can thus choose, for example, to flood the interior of the casing before allowing the fluid to penetrate the batteries.

[0044] Advantageously, said at least one battery is enclosed in said bodywork, directly or enclosed in a said envelope, said bodywork comprising at least one orifice opening to the outside of said vehicle and closable by a safety hatch movable between a closed position and an open position and vice versa, said at least one orifice being arranged to guide a said flow of cooling and / or extinguishing fluid in said at least one channel, and said vehicle comprises control means which are arranged to monitor the temperature of each said battery, and in the event of a temperature being found to be higher than a predetermined temperature, generate internal alert and evacuation signals to the occupants of the vehicle and external alert signals, unlock the exits of said vehicle, and trigger the opening of each said safety hatch.

[0045] Thus the user of the vehicle and its passengers are protected, third parties are warned, and emergency services can intervene.

[0046] Advantageously again, when the vehicle comprises at least one reservoir of cooling and / or extinguishing fluid, the vehicle also comprises means for pressurizing this fluid, and the control means are arranged to, in the event of a temperature being observed to be higher than a predetermined temperature, open a valve or similar to deliver this fluid into at least one suitable channel, at a pressure generated by these pressurizing means, higher than the pressure predetermined by the manufacturer to rupture each safety capsule concerned.

[0047] Thus the user of the vehicle and its passengers are protected until help arrives, particularly in the event of a serious incident requiring the vehicle occupants to be extricated.

[0048] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates an electric or hybrid motor vehicle, comprising an envelope, consisting of a battery pack, containing at least one battery, and an insulated battery, the casing and each battery each comprising a safety capsule according to the invention, at the outlet of a channel supplied with cooling and / or extinguishing fluid by an internal reservoir and / or by a chute opening to the outside by an orifice accessible to the emergency services and concealable by a hatch controlled by control means, which monitor the temperature of each battery or casing by means of temperature sensors, the connections with the control means being shown in broken lines; [Fig.2] schematically illustrates, in cross-section, an advantageous variant of a safety capsule covering a battery or an enclosure: a fixing plate carries a tube, inside which is arranged a spacer carrying an axial perforating element. The tube carries a deformable and tearable cover, comprising rupture incipients. An inerting chute is inserted on the tube in a sealed manner. This inerting chute is fixed to a fluid guide channel, so that only destruction of the cover allows the passage of the cooling or / and extinguishing fluid to the battery or enclosure concerned; the hollow arrow illustrates the direction of the fluid flow during a cooling or extinguishing maneuver; [Fig.3] illustrates schematically, in exploded perspective, certain components of the safety capsule of [Fig.2]: on the left the spacer fitted with the perforating element, at the top the cover with its rupture incipients in broken line, in the middle the chute cut by a median plane and comprising a groove for housing the spacer, at the bottom the plate; [Fig.4] schematically illustrates, in side view and in transparency of the cover, the cooperation between the cover and the perforating element of [Fig.2] in different stages: on the left, in reference A, the normal operation of the vehicle, without flow of fluid on the cover; then, from left to right: in reference B, triggering of a flow of fluid on the cover and beginning of deformation of the latter by a hollow in its center; in reference C, continuation of the flow, with a pressure higher than a predetermined pressure, and contact between the cover, whose hollow has deepened, and the tip of the perforating element; in reference D, continuation of the flow with tearing of the cover by the perforating element; in reference E, continuation of the flow in the largest passage section, with the cover completely torn; [Fig.5] schematically illustrates, in top view and in transparency of the operculum, the cooperation between the operculum and the perforating element of [Fig.2] in different stages of [Fig.4]: on the left in reference A, the operation normal of the vehicle, without fluid flow on the cover; then, from left to right: in mark D the tearing of the cover by the perforating element along tear lines corresponding substantially to the beginnings of rupture visible in [Fig.3], and in mark E the full passage of the fluid; - [Fig.6] schematically illustrates the operculum, in perspective and in transparency, on the left in full and with its beginnings of rupture, in the rest position of mark A, in normal operation of the vehicle, without fluid flow on the cover; then, on the right part of the figure, in perspective cut by a median plane: this same mark A, in mark B after triggering of a fluid flow on the cover and beginning of deformation of the latter by a hollow in its center; in mark D, continuation of the flow with tearing of the cover in its center by the perforating element and beginning of extension of the tear along tear lines corresponding substantially to the beginnings of rupture visible in [Fig.3], and in mark E, the cover completely torn; - [Fig.7] illustrates schematically and, in partial perspective, the interior of a battery pack, equipped with a safety capsule according to the invention.

[0049] The objective is to provide direct access to the battery to emergency services, compatible with extrication to be able to flood it and inert it with a circulation of fluid, in particular and not limited to water.

[0050] [Fig.l] schematically illustrates an electric or hybrid motor vehicle 1 according to the invention, comprising at least one battery 3 for storing electrical energy, and comprising a body 2 comprising at least one channel 6.

[0051] This at least one battery 3 is enclosed in the bodywork 2, directly or enclosed in an envelope 7 which the vehicle 1 comprises, itself enclosed in the bodywork 2. This envelope 7 can be a battery pack, comprising one or more batteries 3, and, more particularly, can be closed by delimiting a chamber 9 which contains each battery.

[0052] This at least one channel 6 is arranged to guide a flow of cooling and / or extinguishing fluid, from at least one tank 60 that the vehicle 1 comprises, and / or from at least one external supply station such as a fire hose, a pipe, or the like, to at least one fluid inlet 8 that the at least one battery 3 comprises, and / or that at least one such casing 7 enclosing the at least one battery 3 comprises.

[0053] According to the invention, the at least one fluid inlet 8 comprises a safety capsule 10 closing the at least one fluid inlet 8 when the fluid pressure in the at least one channel 6 is lower than a predetermined pressure, and this safety capsule 10 is arranged to break and allow passage to a said fluid cooling and / or extinguishing when the fluid pressure in the at least one channel 6 is higher than the predetermined pressure.

[0054] In a non-limiting variant, this predetermined pressure is close to 3 bars.

[0055] In a variant, and as visible in [Fig.l], the vehicle 1 comprises at least one tank 60 containing cooling and / or extinguishing fluid; this fluid may be liquid, such as water, or water with at least one additive added thereto such as a wetting and / or foaming agent and / or a floating film-forming agent; this fluid may also be gaseous, such as nitrogen or the like, preventing further combustion. This tank 60 may in particular, but not limited to, be a pressurized fire extinguisher, with an opening valve controlled by at least one temperature sensor, or by control means 20 that the vehicle 1 comprises.

[0056] This reservoir variant can be juxtaposed with, or replaced by, a configuration also visible in [Fig.l], in which the bodywork 2 comprises at least one orifice 4 opening onto the exterior of the vehicle 1. Such an orifice 4 is arranged to guide such a flow of cooling and / or extinguishing fluid into at least one channel 6, from an external supply station that can be manipulated by a fire-fighting service, or by an electrical energy charging center manager, or by the user of the vehicle. This access that can be used by the emergency services is connected via at least one channel 6, comprising an inlet chute, to provide the link between the exterior of the vehicle and an enclosure 7, in particular a battery pack, installed for example under the floor of the vehicle.

[0057] In an alternative embodiment, visible in [Fig.l], at least one orifice 4 can be closed by a safety hatch 5 which can move between a closed position and an open position and vice versa.

[0058] In another variant embodiment not illustrated, at least one orifice 4 comprises a valve which remains in a default closed position, as long as no pressure is exerted from outside the vehicle towards the channel 6, and which is movable towards an open position when pressure is exerted from outside the vehicle towards the channel 6, either mechanically with a fire hose or a tool, or hydraulically or pneumatically when a fluid, liquid or gaseous, is supplied at a pressure higher than that prevailing in the channel 6.

[0059] The safety capsule 10 advantageously comprises a self-piercing cover, the purpose of which is to provide access to the interior of the battery and allow the cooling and / or extinguishing fluid, in particular water, to penetrate therein. The ultimate aim is to generate a circulation of water that is sufficiently effective to cool and inert the battery to secure the vehicle. This invention notably presents a mechanism access by self-piercing cover under water pressure opening into the traction battery.

[0060] In a particular embodiment and as visible in [Fig.l], [Fig.2], [Fig.3], [Fig.4], [Fig.5], the safety capsule 10 comprises a cover 11 which is deformable under the action of a fluid pressure in the at least one channel 6 greater than the predetermined pressure, from a rest position when the fluid pressure in the at least one channel 6 is lower than the predetermined pressure, to a fluid passage position when the fluid pressure in the at least one channel 6 is greater than the predetermined pressure. The fluid pressure then causes, directly or indirectly, the irreversible tearing of the cover 11.

[0061] More particularly still, as visible in [Fig.l], [Fig.2], [Fig.3], [Fig.4], [Fig.5], the safety capsule 10 comprises at least one perforating element 12, which is arranged to pierce the seal 11 when the fluid pressure in the at least one channel 6 is greater than the predetermined pressure: this fluid pressure deforms the seal 11, brings the seal 11 into a contact position between the seal 11 and the at least one perforating element 12, then the fluid pressure causes the seal 11 to tear, and / or the at least one perforating element 12 to pass through the seal 11.

[0062] More particularly, as visible in [Fig.3] and [Fig.6], this cover 11 comprises at least one rupture initiation point 110, which is arranged to rupture, either under the effect of a fluid pressure in the at least one channel 6 which is greater than the predetermined pressure, the cover 11 then tearing preferentially along tear lines 111 corresponding substantially to these rupture initiation points 110, or during a perforation of the cover 11 by the at least one perforating element 12.

[0063] The tearing of the cover 11 is thus programmed by propagation of cracks.

[0064] To improve the propagation of tears, the perforating element 12 may have a cross shape, in addition to its tip.

[0065] More particularly, the cover 11 is made of aluminum alloy, or ductile steel sheet, or composite material that melts under a pressure greater than the predetermined pressure.

[0066] More particularly, the operculum has a thickness of between 0.25 mm and 0.50 mm.

[0067] The variant with perforating element 12 is often preferred, because the use of a safety capsule 10 with cover 11 alone, without a point, requires lower calibrations which may prove incompatible with the internal pressures in the battery pack.

[0068] More particularly, as visible in [Fig.2], the safety capsule 10 comprises a fixing plate 13 receiving a tube 14, inside which is arranged a spacer 15, such as a hoop or the like, carrying at least one perforating element 12. The tubing 14, or the fixing plate 13 itself, carries the cover 11. An inerting chute 16 is inserted without play or crimped onto the cover 11, or onto the tubing 14, or onto the fixing plate 13 or a collar carried by the latter, in a sealed manner. This inerting chute 16 is fixed to a channel 6 or which forms the end of such a channel 6, so that only destruction of the cover 11 allows the passage of the cooling or / and extinguishing fluid towards the battery 3 or the casing 7 concerned.

[0069] In a particular embodiment, and as visible in [Fig.l], the vehicle 1 comprises at least one casing 7 containing at least one battery 3, and this at least one casing 7 comprises at least one safety capsule 10 at the outlet of the at least one channel 6. More particularly, this at least one casing 7 contains, in a chamber 9 which is arranged to contain cooling and / or extinguishing fluid, at least one battery 3. Even more particularly, this chamber 9 contains at least one battery 3, which itself comprises at least one safety capsule 10: the chamber 9 then forms a channel for conveying the cooling and / or extinguishing fluid to the battery 3.

[0070] More particularly and non-limitingly, the predetermined pressure to which the at least one safety capsule 10 that this envelope 7 comprises is calibrated is different from the predetermined pressure to which the at least one safety capsule 10 that the at least one battery 3 comprises is calibrated.

[0071] More particularly, and as visible in [Fig.l], the vehicle 1 comprises control means 20, which are arranged to monitor the temperature of each battery 3 by means of first temperature sensors 21, and / or of each casing 7 by means of second temperature sensors 27, and in the event of a temperature being found to be higher than a predetermined temperature, generate internal alert and evacuation signals to the occupants of the vehicle and external alert signals, unlock the exits of the vehicle 1.

[0072] More particularly still, and as visible in [Fig.l], the bodywork 2 comprises at least one orifice 4 opening to the outside of the vehicle 1 and closable by a safety hatch 5 movable between a closed position and an open position and vice versa, and these control means 20 are arranged to, in the event of a temperature being observed to be higher than a predetermined temperature, trigger the opening of each safety hatch 5 by the release of a closure 25.

[0073] More particularly, and as visible in [Fig.l], when the vehicle 1 comprises at least one reservoir 60 of cooling and / or extinguishing fluid, the vehicle 1 also comprises means for pressurizing this fluid 61, and the control means 20 are arranged so that, in the event of a temperature being observed to be higher than a temperature predetermined, open a valve or similar to deliver this fluid into at least one suitable channel 6, at a pressure generated by these pressurizing means, higher than the pressure predetermined by the manufacturer to rupture each safety capsule 10 concerned.

[0074] Advantageously, each channel 6 is provided with at least one non-return valve (not illustrated), so as to direct, after each possible diversion, the fluid towards a fluid inlet 8 provided with a safety capsule 10.

[0075] In short, the invention makes it possible to provide direct access to each battery to emergency means or services, in particular compatible with extrication, in order to be able to flood and inert each battery with a circulation of cooling and / or extinguishing fluid.

[0076] The choice of a self-piercing cover provides access to the interior of the battery and allows this fluid to penetrate.

[0077] The invention makes it possible to resolve the problems of uncontrollable battery fires using traditional extinguishing methods (watering the battery pack) and the risks of a new fire starting due to the presence of residual energy in the pack. It constitutes a significant advance compared to solutions on the market, which require waiting for the vehicle to be more or less completely ignited before gaining access to the battery.

[0078] By this new device according to the invention, access is possible preventively (as soon as there is a risk of thermal runaway), or as soon as thermal runaway occurs, or as soon as the emergency services arrive. This solution offers a possibility of effective action for firefighters for all cases of thermal runaway occurrence and in particular in confined environments (underground parking, tunnel, ship, private garage) where waiting is not an option or during extrication following an accident, with occupants in a vehicle to be freed after a collision for example.

[0079] The supply of cooling and / or extinguishing fluid, in particular water, into the battery makes it possible to stop thermal propagation from cell to cell, because, as soon as thermal runaway is triggered, access to the device is possible, making it possible to lower the temperature and discharge the battery of its energy by creating an electrolysis phenomenon.

[0080] This solution allows complete and definitive inerting of the battery which guarantees the safety of transport and storage, no resumption of fire being then possible.

[0081] Thus the invention solves the problem posed by generating a circulation of fluid sufficiently effective to cool and inert the battery to secure the vehicle. The irreversible tearing of the cover requires intervention on the battery and / or on the envelope surrounding the battery(ies), the exchange of the battery if necessary, and a thorough inspection completed by the installation of a new safety capsule if the vehicle is put back into service following the intervention in the repair circuit.

[0082] The invention makes it possible to easily install a device for inlet of cooling and / or extinguishing fluid, or water, directly into the battery pack in the event of thermal runaway in order to allow a rapid and applicable inerting solution for all life situations and in particular in the event of a collision, with occupants in the vehicle. This installation can be limited to the equipment of the battery and / or the battery pack, with minimal impact on the design of the vehicle body. This solution is economical, and the safety capsule can easily be replaced by another model.

[0083] The advantages over the prior art are multiple, and the invention makes it possible in particular to: - stop the spread in less than 5 minutes (compared to several hours) thus reducing the intervention time of emergency services; - discharge the battery of its energy to avoid any restart of thermal runaway, and thus secure the transport and storage of the vehicle; - limit the quantity of fluid used and polluted during the intervention; - limit investment in after-sales equipment for the storage of burnt batteries; - directly access the battery during extrication; - access the battery directly as soon as there is a risk of a runaway battery thermal, or upon its departure, or upon arrival of emergency services without combustion of parts or thermal fuses; - direct access to the battery without causing toxic fumes to enter the vehicle interior; - be compatible with ENCAP (European Car Assessment Programme) criteria at the highest level; - avoid adding an active mechanism to allow access to the battery (the system according to the invention is passive); - limit the security study only to the platform, battery pack, and battery perimeters; - maintain the ventilation gas evacuation strategy by setting the seal high, thus avoiding unwanted tears due to internal pressure in the pack; - fill the battery more easily and quickly, compared to a pilot valve sensitive to pressure drops; - prevent malicious acts with invisible access known only to emergency services; - have a specific circulation of the fluid (dedicated and optimized inlet, and outlet through degassing valves) to improve the cooling and inerting of the battery pack; - carry out the assembly in a single step of the tearing function of the cover (piercing element and cover); - guarantee the tightness of the pack when the system is at nominal; - ensure that unintentional opening is not possible, calibrated for a fluid pressure greater than a predetermined pressure, for example 3 bars, in the conduit.

[0084] The invention provides a good safety solution, the safety capsule is easy to install after a simple drilling in a partition, and does not require an active system at the battery level, it can therefore operate in the event of failure of the vehicle's services in the event of an accident. Reconditioning for another use (for example, a thermal vehicle) of a battery pack or a battery equipped with a safety capsule is easy by removing the capsule and simply sealing its housing.

[0085] Finally, the components are easy to produce, and the invention is inexpensive in relation to the progress in safety that it brings.

Claims

Claims

1. Electric or hybrid motor vehicle (1) comprising at least one battery (3) for storing electrical energy, and a body (2) comprising at least one channel (6) arranged to guide a flow of cooling or / and extinguishing fluid, from at least one reservoir (60) included in said vehicle (1) or / and from at least one external supply station, to at least one fluid inlet (8) included in said at least one battery (3), or / and included in at least one casing (7) enclosing said at least one battery (3) and included in said vehicle (1), characterized in that said at least one fluid inlet (8) comprises a safety capsule (10) closing said at least one fluid inlet (8) when the fluid pressure in said at least one channel (6) is lower than a predetermined pressure,and which safety capsule (10) is arranged to break and allow passage to a said cooling and / or extinguishing fluid when the fluid pressure in said at least one channel (6) is greater than said predetermined pressure, said safety capsule (10) comprising a cover (11) which is deformable under the action of a fluid pressure in said at least one channel (6) greater than said predetermined pressure, from a rest position when the fluid pressure in said at least one channel (6) is lower than said predetermined pressure, to a fluid passage position when the fluid pressure in said at least one channel (6) is greater than said predetermined pressure and causes, directly or indirectly, the irreversible tearing of said cover (11),said safety capsule (10) comprising at least one perforating element (12) arranged to pierce said seal (11) when the fluid pressure in said at least one channel (6) is greater than said predetermined pressure and when said fluid pressure deforms said seal (11) until said seal (11) is torn, and / or said at least one perforating element (12) passes through said seal (11).,

2. Motor vehicle (1) according to claim 1 characterized in that said cover (11) comprises at least one rupture initiator (110) arranged to break upon perforation of said cover (11) by said at least one perforating element (12).

3. Motor vehicle (1) according to claim 1 characterized in that said cover (11) comprises at least one rupture initiator (110) arranged to break under the effect of a fluid pressure in said at least one channel (6) greater than said predetermined pressure.

4. Motor vehicle (1) according to one of claims 1 to 3, characterized in that said cover (11) is made of aluminum alloy, or ductile steel sheet, or composite material which melts under a pressure greater than said predetermined pressure.

5. Motor vehicle (1) according to one of claims 1 to 4, characterized in that said cover (11) has a thickness of between 0.25 mm and 0.50 mm.

6. Motor vehicle (1) according to one of claims 1 to 5 characterized in that said vehicle (1) comprises at least one said envelope (7) comprising at least one said safety capsule (10) at the outlet of said at least one channel (6), and enclosing, in a chamber (9) arranged to contain said cooling and / or extinguishing fluid, at least one said battery (3) which itself comprises at least one said safety capsule (10).

7. Motor vehicle (1) according to claim 6 characterized in that said predetermined pressure to which said at least one safety capsule (10) of said casing (7) is calibrated is different from said predetermined pressure to which said at least one safety capsule (10) that said at least one battery (3) comprises is calibrated.

8. Motor vehicle (1) according to one of claims 1 to 7 characterized in that said at least one battery (3) is enclosed in said bodywork (2), directly or enclosed in a said casing (7), said bodywork (2) comprising at least one orifice (4) opening to the outside of said vehicle (1) and closable by a safety hatch (5) movable between a closed position and an open position and vice versa, said at least one orifice (4) being arranged to guide a said flow of cooling and / or extinguishing fluid in said at least one channel (6), and in that said vehicle (1) comprises control means (20) arranged to monitor the temperature of each said battery (3), and in the event of a temperature being found to be higher than a predetermined temperature, generate internal alert and evacuation signals to the occupants of the vehicle and external alert signals, unlock the exits of said vehicle (1), and trigger the opening of each said safety hatch (5).

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