HOT-MELTING CAP

Description

[0001] The present invention relates to a device for extinguishing a fire, and more particularly to a device for extinguishing a fire within an electrical storage device of a vehicle.

[0002] Electrical storage devices, otherwise known as batteries, are commonly used in hybrid and / or electric vehicles. Such storage devices can, for example, supply electrical energy to an electric motor on board the motor vehicle. However, batteries can potentially catch fire, for example, in the event of a vehicle fire, for example in the event of vandalism of the vehicle or following a traffic accident. The thermal runaway phenomenon of the electrochemical cells inside the battery can therefore potentially be triggered due to the presence of a very high release of heat near the batteries, for example during a vehicle fire.

[0003] We thus know the use of a device for extinguishing a fire developing within the electrical storage device, comprising at least one bottle filled with at least one gas capable of stopping the spread of the fire. In particular, document EP2556857A1 discloses a gas bottle whose closing cap is pierced by means of a needle, the needle being actuated under the effect of the melting of a heat-sensitive member which retains it.

[0004] One of the disadvantages of such an extinguishing device mentioned above lies in particular in the fact that its implementation is expensive and requires regular maintenance and servicing. The aim of the present invention is therefore to simplify the use of extinguishing devices by making their actuation, that is to say the release of the gas capable of stopping the spread of the fire, solely mechanical and by reducing the number of parts necessary for this actuation.

[0005] The invention therefore relates to a device for extinguishing a fire in an electrical storage device of a vehicle, the extinguishing device comprising at least one cap and a bottle containing at least one fire extinguishing gas, the bottle comprising a closing cap and delimiting a volume containing the gas, the cap comprising at least one piercing device, the extinguishing device being characterized in that the piercing device is made of an at least partially heat-meltable material, the cap being capable of being secured to the bottle in such a way that the piercing device breaks the closing cap of said bottle and the cap hermetically closes the volume of the bottle.

[0006] The fire extinguishing device within the electrical storage device, in other words batteries, can be used with an electric and / or hybrid motor vehicle, but also in stationary storage. Such batteries make it possible in particular to supply electrical energy to an electric motor housed within the vehicle, thus ensuring the latter's movement. The extinguishing device then has the function of combating the spread of a fire within the electrical storage device. To do this, the extinguishing device comprises at least the gas cylinder and the cap which makes it possible to hermetically seal the volume of the cylinder while allowing the gas to escape under the effect of at least one environmental parameter, here the air temperature in the electrical storage device.

[0007] It is then understood that the device for piercing the cap is capable on the one hand of breaking the closure seal, releasing the gas contained in the volume of the bottle, and on the other hand of blocking the evacuation of this gas from the bottle, that is to say towards the external environment of said volume. Such hermeticity of the volume of the bottle is then ensured at least in part by the piercing device.

[0008] The piercing device comprises at least a body and a tip both comprising a hot melt material.

[0009] It is understood here that the tip has the function of breaking the closure seal of the gas bottle and is configured to extend at least partially into the volume of the bottle, once the closure seal is broken. It is further understood that the tip, when it extends into the volume of the bottle, participates in sealingly closing the volume of said bottle, in combination with the body.

[0010] A hot-melt material is then understood to mean that the material is sensitive to heat. In other words, the hot-melt material is capable of changing state under the effect of heat and in particular of passing from a solid state to a liquid state. In other words, the piercing device is capable of melting under the effect of heat, at least from a threshold temperature, for example 80°C.

[0011] According to non-limiting examples of the invention, the body and the tip may be made of polyethylene, and / or polypropylene, and / or polyamide, and / or polybutylene terephthalate, and / or Poly Acrylonitrile butadiene styrene.

[0012] The cap comprises a base provided with an openwork wall suitable for the passage of gas, the base comprising at least one heat-resistant material, the openwork wall being arranged around the body of the piercing device and the base comprising at least one means for fixing the cap to the bottle.

[0013] The base of the cap then helps to keep the piercing device in position on the bottle, so that the latter ensures the airtightness of said bottle. Heat-resistant material is understood to mean that the base is capable of withstanding high temperatures, in particular higher than the melting temperature of the hot-melt material constituting the piercing device. In other words, the base has a melting temperature, for example, higher than 250°C. According to an example of the invention, the entire base is formed from the heat-resistant material.

[0014] According to non-limiting examples of the invention, the heat-resistant material may be a synthetic material of the polyetheretherketone type, and / or polyimide and / or epoxy.

[0015] The term "perforated wall" means that it comprises at least one window formed in its thickness, so as to put an internal volume of the base into communication with the external environment thereof. It is then understood that following the melting of at least one part of the piercing device, the perforated wall allows the passage of gas from the volume of the bottle to the external environment of the bottle. According to an example of the invention, the wall may comprise a plurality of windows which extend peripherally around the base.

[0016] The fixing means extends around the periphery of the tip of the drilling device.

[0017] The base comprises at least one fixing wall arranged around the tip of the piercing device, the means for fixing the cap being a thread formed on the fixing wall capable of cooperating with a complementary thread formed on the bottle.

[0018] The openwork wall is extended by a fixing wall which comprises the fixing means, here the thread, for example internal or external. According to one example, the fixing wall comprises an internal face, facing the tip of the drilling device, the internal thread being formed on said internal face of the fixing wall.

[0019] The bottle comprises an opening intended to be covered by the closure cap before the cap is fitted to the bottle, the opening being made in particular at the end of a neck of the bottle. It is then understood that the complementary thread is formed at an external periphery of the neck of the bottle, so that it is able to cooperate with the thread of the fixing wall of the base of the cap.

[0020] It is then understood that according to this exemplary embodiment of the invention, the cap is screwed onto the bottle in such a way that the point breaks the closure cap, the retention of the cap on the bottle by means of the thread and the complementary thread ensuring the hermetic closure of the volume of the bottle, in combination with the piercing device.

[0021] According to an alternative embodiment of the invention, the means for fixing the cap to the bottle is a force-fitting of the base onto the bottle.

[0022] According to an example of the invention, the internal face of the fixing wall may comprise an excess thickness which extends peripherally around the tip of the piercing device, the excess thickness participating in retaining the cap on the bottle. In other words, the excess thickness participates in reducing a perimeter defined by the fixing wall, thus participating in achieving force-fitting on the bottle.

[0023] According to a characteristic of the invention, a sealing gasket is arranged peripherally around the tip of the drilling device.

[0024] It is understood that the seal increases the hermeticity of the closure of the volume of the bottle by the cap, in particular when the said cap is force-fitted onto the bottle.

[0025] According to a characteristic of the invention, the drilling device comprises at least 5% of a mineral material.

[0026] The mineral material constituting at least part of the piercing device makes it possible to increase the hardness of the piercing device. This reinforces the ability of the piercing device to break the sealing seal without altering its heat-melting property.

[0027] According to a characteristic of the invention, the gas cylinder comprises at least in part carbon dioxide. Carbon dioxide has in particular the property of allowing the extinction of the fire developing within the electrical storage device, in particular by driving out at least in part the oxygen present in the electrical storage device.

[0028] According to a characteristic of the invention, the piercing device has a melting temperature at least greater than 80°C. It is understood that from 80°C, the piercing device will pass from the solid state to the liquid state, thus allowing the passage of gas from the volume of the bottle to the external environment of the latter, in particular by means of the perforated wall of the base. According to one example, the melting temperature of the piercing device is greater than 80°C. Advantageously, the melting temperature of the piercing device is less than 120°C.

[0029] The invention further relates to an electrical storage device for a motor vehicle comprising at least one peripheral wall and at least one fire extinguishing device according to the preceding characteristics.

[0030] The electrical storage device, otherwise known as a battery pack, is used in particular in so-called hybrid or all-electric vehicles, in order to ensure the supply of electricity to at least one electric motor. The peripheral wall then helps to delimit a space in which storage cells are housed, which form the electrical storage device.

[0031] According to a feature of the electrical storage device, the extinguishing device is housed in the peripheral wall. More specifically, at least one cavity is formed in a thickness of the peripheral wall of the electrical storage device, the extinguishing device being housed in said cavity. According to one example, this cavity opens on an edge of the peripheral wall.

[0032] According to a characteristic of the storage device, the peripheral wall comprises at least one cutout, the cap comprising a base provided with an openwork wall suitable for the passage of gas, the openwork wall of the base of the cap of the extinguishing device being opposite the cutout.

[0033] It is understood that the cutout is made at the cavity which houses the extinguishing device, such that the cutout is formed opposite the perforated wall of the cap. In other words, the cutout connects a volume of the cavity with an internal space of the electrical storage device where the electrical cells are arranged. Advantage is taken of such a characteristic in that it makes it possible to increase the diffusion of the gas from the gas cylinder to the internal space of the electrical storage device.

[0034] The invention further relates to a method of assembling the extinguishing device according to the preceding characteristics, the method comprising at least one step during which the cap is placed opposite the closed closure seal of the bottle, then at at least one other subsequent step, the cap is fixed to the bottle by a fixing means, such that the piercing device breaks the closure seal, the cap hermetically closing the volume of the bottle.

[0035] It is therefore understood that the combination between the structure of the piercing device and the holding of the cap thanks to its fixing means ensures the hermetic closure of the gas bottle. It is also understood that the casting of the piercing device, comprising a thermofusible material, ensures the passage of the gas from the volume of the bottle to a volume outside the bottle, here the internal space of the electrical storage device, allowing the fire to be extinguished.

[0036] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below for information purposes in relation to drawings in which: [ Fig 1 ] is a general view of an electrical storage device comprising an extinguishing device according to the invention; [ Fig 2 ] is a schematic view of the extinguishing device of the figure 1 comprising at least one cap and one gas bottle; [ Fig 3 ] is a general view of the fire extinguishing device cap figure 1 ; [ Fig 4 ] is a schematic longitudinal sectional view of the plug of the fire extinguishing device figure 1 comprising at least one means of attachment to the bottle according to a first exemplary embodiment; [ Fig 5 ] is a schematic longitudinal sectional view of the plug of the fire extinguishing device figure 1 comprising at least one means of attachment to the bottle according to a second exemplary embodiment; [ Fig 6 ] is a schematic view of at least a portion of the assembly of the plug of the extinguishing device of the figure 1 on the bottle of the latter; [ Fig 7 ] is a schematic view of the extinguishing device of the figure 1 wherein the piercing device is in a molten state.

[0037] It should first be noted that while the figures set out the invention in detail for its implementation, these figures can of course be used to better define the invention, where appropriate. It should also be noted that these figures only set out examples of embodiments of the invention. Finally, the same references designate the same elements in all the figures.

[0038] There figure 1 illustrates an electrical storage device 1, for example of a motor vehicle, in which is housed an extinguishing device 2 according to the invention. The electrical storage device 1, otherwise called a battery pack, can in particular be used within a hybrid or electric motor vehicle for which it provides the supply of electrical energy to at least one electric motor, not shown, such a motor ensuring the movement of the vehicle.

[0039] The electrical storage device 1 comprises at least one peripheral wall 4 which delimits a space 6 of said storage device, the space 6 being able to house, for example, electrical cells, not shown. As visible figure 1 , the peripheral wall 4 of the electrical storage device 1 comprises at least one cavity 8 formed in its thickness, the extinguishing device 2 according to the invention being housed in said cavity 8.

[0040] The extinguishing device 2 has the function of at least preventing the spread of fire within the electrical storage device 1, in particular by releasing at least one fire-extinguishing gas. More precisely, the gas may be, for example, at least carbon dioxide making it possible to limit the spread of fire by filling the space 6 of the electrical storage device 1, thus ensuring the depletion of the fire in oxidant.

[0041] The extinguishing device 2, visible at the figure 2 in a configuration before assembly, comprises at least one cap 10 and a bottle 12 containing at least the fire extinguishing gas. More precisely, the bottle 12 of the extinguishing device 2 delimits a volume 14 in which the gas is contained. The gas bottle 12 extends mainly in a longitudinal direction L and comprises at least one opening 16 at one of its longitudinal ends 18. It is then understood that the opening 16 has the function, on the one hand, of allowing the entry of the gas into the volume 14 of the bottle 12, and on the other hand the exit of said gas, in particular when the extinguishing device 2 is housed in the electrical storage device, under certain environmental conditions which will be detailed later.

[0042] In the configuration of the figure 2 , the volume 14 of the gas bottle 12 is closed by means of a closure cap 20 covering the opening 16 of the gas bottle 12. It is then understood that the closure cap 20 has the function of preventing the gas from escaping from the volume 14 of the bottle 12. According to a non-limiting example of the invention, the closure cap 20 is an easily tearable sheet such as aluminum or a plasticized paper film.

[0043] The cap 10 of the extinguishing device 2 comprises at least one piercing device 22 and a base 24 provided with an openwork wall 26. The piercing device 22 then has the function, on the one hand, of breaking the closure cap 20 of the bottle 12 previously described, and on the other hand of ensuring at least in part the hermetic closure of the bottle 12 once the closure cap 20 is broken, in cooperation with the base 24 of the cap 10. Hermetic closure is then understood to mean that the cap 10 prevents the gas from the bottle 12 from escaping outside the volume 14 of the latter, towards the space of the electrical storage device. Such cooperation between the cap 10 and the bottle 12 will be described later in the detailed description, in particular at figure 6 .

[0044] The plug 10 will now be described in more detail with reference to the figures 3 à 5 .

[0045] The piercing device 22 of the stopper 10 comprises at least one body 28 and a tip 30 which extends from the body 28 of the stopper 10. More precisely, the tip 30 extends from the body 28 of the stopper 10 in the longitudinal direction L of the gas bottle 12. It is then understood that the piercing device 22 has an elongated shape in the longitudinal direction L of the bottle 12. According to the example of the invention, the body 28 of the piercing device 22 has a cylinder shape of which a central axis C of revolution is defined, parallel to the longitudinal direction L of the bottle. Thus, the tip 30 has a conical shape of which one end forming a bevel of the cone is positioned in the central axis C of the body 28 and opposite the latter.

[0046] According to the invention, the body 28 and the tip 30 of the piercing device 22 both comprise a hot-melt material. Advantageously, the body 28 and the tip 30 of the piercing device 22 are entirely made of the hot-melt material. By hot-melt material is meant the fact that the body 28 and the tip 30 of the piercing device 22 are capable of passing from a solid state to a liquid state under the effect of a determined temperature. Thus, the body 28 and the tip 30 are capable of softening when the temperature reaches at least a threshold temperature, then of melting when the temperature reaches at least a melting temperature. The melting temperature from which the body 28 and the tip 30 melt is here at least 80°C.It is then understood that when the temperature present in the space of the electrical storage device reaches at least the melting temperature of the body 28 and the tip 30, the latter change state, as mentioned above.

[0047] According to non-limiting examples of the invention, the body 28 and the tip 30 may be made of polyethylene, and / or polypropylene, and / or polyamide, and / or polybutylene terephthalate, and / or Poly Acrylonitrile butadiene styrene.

[0048] According to an example of the invention, the body 28 and the tip 30 may comprise at least 5% of a mineral material. The mineral material which at least partly composes the body 28 and the tip 30 then has the effect of reinforcing the structure of the latter, in particular by hardening it. Such a composition of at least 5% of mineral material also has the advantage of preserving the heat-melting property of the body 28 and the tip 30 of the piercing device 22. The rigidity obtained by means of the incorporation of the mineral material guarantees the piercing of the closure cap 20 by the tip 30 when the cap 10 is assembled to the bottle 12.

[0049] The base 24 of the cap 10 comprises at least the perforated wall 26 and at least one fixing wall 32. More precisely, the perforated wall 26 of the base 24 is arranged around the body 28 of the piercing device 22, while the fixing wall 32 is arranged around the tip 30 of said piercing device 22. It is then understood that the perforated wall 26 of the base 24 extends at the periphery of the body 28 of the piercing device 22 mainly in the longitudinal direction L of the bottle and in such a way that it is at a first non-zero distance D1 from said body 28, the first distance D1 being taken in a radial direction of the body 28 relative to its central axis C, as is apparent from the figure 4 .

[0050] The term “perforated wall 26” then means that the latter comprises at least one through window 34. More precisely and as illustrated according to the example of the invention, the perforated wall 26 comprises a plurality of windows 34 which extend peripherally around the body 28 of the piercing device 22.

[0051] The fixing wall 32 of the base 24 extends peripherally around the tip 30 of the piercing device 22, mainly along the longitudinal direction L of the bottle. More precisely, the fixing wall 32 extends at least in part at a second non-zero distance D2 from the tip 30, the second distance D2 being taken along the radial direction of the body 28 along its central axis C. The shape of the tip 30 being conical, it is understood that the second distance D2 which separates the tip 30 from the fixing wall 32 increases as one moves away from the body 28 from the piercing device 22, along the longitudinal direction L of the bottle. Furthermore, the second distance D2 is strictly less than the first distance D1 which separates the body 28 from the piercing device 22 and the perforated wall 26.

[0052] A first end 36 of the cap 10 and a second end 38 of the cap 10 are defined, opposite one another, along the longitudinal direction L of the gas bottle. The first end 36 then corresponds to the end located at the level of the perforated wall 26 of the base 24, while the second end 38 corresponds to the end at the level of the fixing wall 32 of the base 24.

[0053] An end disc 40 of the base 24 is arranged at the first end 36 of the plug 10. The end disc 40 is then configured to close the first end 36 of the plug 10, such that the plurality of windows 34 constitutes the only fluid communication between a volume internal to the plug delimited by the perforated wall 26 and an environment external to the plug 10. The end disc 40 comprises an external peripheral edge 41 which has an end disc radius R1 at least equal to a wall radius R2 defined by the perforated wall 26, the external end disc radius R1 and the wall radius R2 being defined relative to the central axis C of the body 28 of the piercing device 22. It is then understood that the end disc 40 is arranged to cover one end of the perforated wall 26, at the first end 36 of the plug 10.

[0054] It is further understood that in a configuration where the temperature in the space of the electrical storage device reaches at least the melting temperature, the piercing device 22 melts and allows circulation of the gas towards the windows 34.

[0055] The base 24 of the plug 10 further comprises at least one connecting disc 44, arranged between the perforated wall 26 and the fixing wall 32 of the base 24. In other words, the connecting disc 44 extends radially around the periphery of the piercing device 22, along the central axis C of the body and in such a way that it connects the perforated wall 26 to the fixing wall 32. The connecting disc 44 further comprises a circular orifice 46, an inner peripheral edge 48 of which extends around the body 28 of the piercing device 22. The inner peripheral edge 48 is in particular adjusted around the body 28, in such a way that said inner peripheral edge 48 and the body 28 are in contact with each other, that is to say at a third zero distance D3, measured along the radial direction of the body 28 relative to its central axis C.According to the illustrated example of the invention, the connecting disc 44 has a connecting disc radius R3 taken between the central axis C and an external edge 50 of the connecting disc 44 at least equal to the wall radius R2 defined previously.

[0056] It is then understood from the above that the particular arrangement of the connecting disc 44 around the body 28 of the piercing device 22 makes it possible to block the circulation of gas between a volume delimited by the fixing wall 32 and the volume delimited by the perforated wall 26.

[0057] According to the invention, the base 24 of the plug 10 comprises at least one heat-resistant material. Heat-resistant material is then understood to mean that the base 24 is capable of withstanding high temperatures, strictly higher than the melting temperature of the piercing device 22 previously explained. More precisely, the heat-resistant material according to the invention is capable of withstanding a temperature at least higher than 250°C, a temperature which should not be reached since the melting of the piercing device will have previously smothered the fire. According to non-limiting examples of the invention, the heat-resistant material may be a plastic material of the polyetheretherketone type, and / or polyimide and / or epoxy.

[0058] According to a characteristic of the invention, the heat-resistant material of the base 24 of the plug 10 may comprise a mineral material. The mineral material constituting at least part of the base 24 makes it possible to increase the mechanical properties and the resistance to high temperatures of the latter.

[0059] Still according to the invention, the base 24 comprises at least one means 52 for fixing the cap 10 to the gas bottle 12. Thus, according to a first example of the invention visible in the figure 4 , the fixing means 52 of the cap 10 is a thread 54, here an internal thread, formed on the fixing wall 32 of the base 24. More precisely, an internal face 56 of the fixing wall 32 is defined as being a face of the fixing wall 32 facing the tip 30 of the piercing device 22. The internal face 56 then comprises at least the thread 54 capable of cooperating with a complementary thread 58 formed at the opening 16 of the bottle 12, as visible in the figure 2 The complementary thread 58 is here produced on an external periphery of a neck 59 of the bottle 12.

[0060] According to a second example of the fixing means 52, visible in figure 5 , the fixing of the cap 10 on the gas bottle 12 is a force-fitting of at least the fixing wall 32 on the neck 59 of the bottle. It should be considered that in the remainder of the description, only the distinct characteristics between the second embodiment and the first embodiment, and in particular the fixing means 52, will be the subject of a detailed discussion. For the common elements, it will be appropriate to refer to the description above.

[0061] An excess thickness 60 extends peripherally from the internal face 56 of the fixing wall 32. More precisely, the excess thickness 60 extends from the internal face 56 at the second end 38 of the cap 10 and peripherally around the tip 30 of the piercing device 22. The excess thickness 60 then has the function of reducing an internal diameter T1 of the fixing wall 32 in order to allow the force-fitting of said fixing wall 32 on the neck 59 of the gas bottle 12, said neck 59 having a neck diameter T2, visible at figure 2 , strictly greater than the internal diameter T1 of the fixing wall 32.

[0062] According to the example of the invention illustrated in the figure 5 , a seal 62 can be arranged in the volume delimited by the fixing wall, between the excess thickness 60 of the latter and the connecting disc 44 described previously. More precisely, the seal 62 extends peripherally around the tip 30 of the piercing device 22. It is then understood that the seal 62 participates in forming a gas seal between the volume of the bottle and the volume delimited by the base 24, when the cap 10 is fixed on the bottle.

[0063] The method of assembling the extinguishing device 2 will now be described in more detail by means of the figure 6 and of the figure 7 .

[0064] In an initial state in which the cap 10 and the gas bottle 12 described above are separated from each other, as seen in the figure 6 , the closing cap 20 of said bottle 12 tightly closes the volume 14 of the bottle 12 containing the gas. The method then comprises at least one step during which the cap 10 is placed opposite the opening 16 of the bottle 12 carrying the closing cap 20. More precisely, the second end 38 of the cap 10 is placed opposite the opening 16 of the gas bottle 12. Thus, the tip 30 of the piercing device 22 is placed opposite the closing cap 20 of the bottle 12.

[0065] Subsequently, at a later stage, the cap 10 is fixed onto the opening 16 of the bottle 12 via the fixing means 52 formed on the fixing wall 32 of the base 24. Thus, in the case where the fixing means 52 corresponds to the thread 54 formed on the internal face 56 of the fixing wall 32, the cap 10 is screwed onto the neck 59 of the bottle 12 by means of the complementary thread 58 formed on said neck 59. More precisely, the cap 10 is screwed onto this neck 59 at least until the tip 30 of the piercing device 22 breaks the closing cap 20 arranged to cover the opening 16 of the bottle 12.

[0066] The particular structure of the cap 10, and in particular the seal between the volume delimited by the fixing wall 32 and the volume delimited by the perforated wall 26, makes it possible to maintain the seal of the gas bottle 12. In other words, although the closing cap 20 of the bottle 12 is broken and allows the passage of gas through the opening 16 of said bottle 12, the structure of the cap 10 described previously and the maintenance in position of the latter on the neck 59, ensures the hermeticity of the closure of said bottle 12.

[0067] According to an alternative arrangement of the extinguishing device, the cap can be fixed to the bottle in such a way that the piercing device completely closes the opening of the bottle. Thus, the tip of the piercing device extends into the volume of the bottle until it meets an edge of the bottle which delimits the opening. This increases the hermetic closure of the gas bottle.

[0068] When the extinguishing device 2 is positioned in the cavity 8 of the electrical storage device 1 as seen in the figure 1 , the increase in temperature within the space 6 of the storage device 1 at least up to the melting temperature, has the effect of causing the piercing device 22 to melt. In this way, the change in state of the piercing device 22 from the solid state at least to the liquid state has the effect of modifying the sealing properties of the plug 10.

[0069] In other words, the casting of the drilling device, as seen in the figure 7 , has the effect of allowing the circulation of gas, in particular at the level of the connecting disc 44 and its circular orifice 46. In fact, the melting of the piercing device generates a space at least between the inner peripheral edge 48 and the piercing device 22, the space between the latter increasing as the piercing device melts. In other words, the inner peripheral edge 48 of the circular orifice 46 and the piercing device 22 are no longer in contact with each other.

[0070] It is then understood that the windows 34 formed in the perforated wall 26 have the function of allowing the diffusion of the gas outside the plug 10, after having passed through the circular orifice 46 of the connecting disc 44.

[0071] According to an advantageous characteristic of the invention visible in the figure 1 , the peripheral wall 4 of the electrical storage device 1 comprises at least one cutout 64, which opens onto the cavity 8 housing the extinguishing device 2, such that the cutout 64 is formed at least partly opposite the perforated wall of the base of the extinguishing device 2. This facilitates the diffusion of the gas from the volume of the bottle to the space 6 of the electrical storage device 1.

[0072] It is understood that the assembly method as well as the structural and functional characteristics relating to the plug 10 which have just been described with the figure 6 , there figure 7 and the figure 1 , apply mutatis mutandis when the means of attachment is the force fitting of the cap onto the opening of the gas cylinder as described in figure 5 .

[0073] Advantage is taken of the extinguishing device as just described in that it allows, by simple means inherent in its structure, to hermetically close the volume of the bottle containing the gas when the storage device is in normal operating conditions, that is to say when the temperature is below the melting temperature of the piercing device, while allowing the release of the gas into the space of said electrical storage device when the temperature exceeds the melting temperature of the piercing device.

[0074] The invention cannot, however, be limited to the means and configurations exclusively described and illustrated, and also applies to all equivalent means or configurations and to any combination of such means or configurations.

Claims

1. Extinguishing device (2) for extinguishing a fire in an electrical storage device (1) of a vehicle, the extinguishing device (2) comprising at least a cap (10) and a bottle (12) containing at least a fire-extinguishing gas, the bottle (12) having a sealing membrane (20) and delimiting a volume (14) containing the gas, the cap (10) comprising at least one piercing device (22), the extinguishing device (2) being characterized in that the piercing device (22) is made from an at least partially hot-melt material, the cap (10) being able to be secured to the bottle (12) so that the piercing device (22) ruptures the sealing membrane (20) of said bottle (12) and so that the cap (10) hermetically seals the volume (14) of the bottle (12), wherein the piercing device (22) comprises at least a body (28) and a spike (30) both containing a hot-melt material, wherein the cap (10) comprises a base (24) provided with a perforated wall (26) able to allow the gas to pass, the base (24) containing at least a heat-resistant material, the perforated wall (26) being positioned around the body (28) of the piercing device (22) and the base (24) comprising at least one fixing means (52) for fixing the cap (10) to the bottle (12), wherein the base (24) comprises at least one fixing wall (32) arranged around the spike (30) of the piercing device (22), the fixing means (52) belonging to the cap (10) being a screw thread (54) formed on the fixing wall (32) and able to collaborate with a complementary screw thread (58) formed on the bottle (12).

2. Extinguishing device (2) according to Claim 1, wherein the fixing means (52) for fixing the cap (10) to the bottle (12) is a force-fitting of the base (24) onto the bottle (12).

3. Extinguishing device (2) according to either one of the preceding claims, wherein the piercing device (22) contains at least 5% of a mineral material.

4. Electrical storage device (1) for a motor vehicle comprising at least a peripheral wall (4) and at least one fire extinguishing device (2) according to any one of Claims 1 to 3.

5. Electrical storage device (1) according to the preceding claim, wherein the extinguishing device (2) is housed in the peripheral wall (4).

6. Electrical storage device (1) according to either one of Claims 4 and 5, wherein the peripheral wall (4) comprises at least one cutout (64), the cap (10) comprising a base (24) provided with a perforated wall (26) able to allow the gas to pass, the perforated wall (26) of the base (24) of the cap (10) of the extinguishing device (2) being positioned facing the cutout (64).

7. Method for assembling the extinguishing device (2) according to any one of Claims 1 to 3, the method comprising at least a step during which the cap (10) is positioned facing the sealed sealing membrane (20) of the bottle (12), and then, in at least one other later step, the cap (10) is fixed onto the bottle (12) by a fixing means (52) so that the piercing device (22) ruptures the sealing membrane (20), the cap (10) then hermetically sealing the volume (14) of the bottle (12).