EP3313536B1 - Fire extinguisher - Google Patents

Description

Background of the invention

The invention relates to a fire extinguisher comprising a pyrotechnic gas generator.

A fire extinguisher is conventionally in the form of a tank comprising an extinguishing agent which is intended to be delivered to the zone of a fire in order to extinguish it. Several types of extinguishers are known from the state of the art.

In particular, the permanent pressurized fire extinguishers comprise a gas pressure tank containing the extinguishing agent or a pressurized gas cylinder in communication with the chamber in which the extinguishing agent is present. In this type of extinguisher, there is therefore permanent storage under pressure of the extinguishing agent or the propellant of the extinguishing agent. In order to use pressurized gas bottle extinguishers, the gas cylinder is first actuated by the user in order to release the pressurizing gas into the chamber comprising the extinguishing agent and then the agent. extinguishing thus pressurized is delivered to the fire zone by manual actuation.

Extinguishers with permanent pressurization have certain disadvantages, in particular the fact of requiring a certain number of monitoring and verification operations (periodic weighing). In addition, since the pressure of the gas varies with the temperature, the operation of this type of extinguishers is sensitive to the temperature. Another drawback is that, during the delivery of the extinguishing agent, the volume available for the gas increases and therefore the pressure of the gas decreases, which results in a reduction in the rate of delivery of the extinguishing agent. and, therefore, a decrease in the effectiveness of the fire extinguisher. In an attempt to overcome this last drawback, it is possible to increase the pressure imposed at the beginning of the delivery of the extinguishing agent, but such a solution leads, for safety reasons, to resort to oversizing the extinguisher and, by Therefore, to increase its size and its cost.

As an alternative to permanent pressurized extinguishers, a second type of extinguisher has been proposed including a pyrotechnic gas generator. The pyrotechnic gas generator makes it possible to produce a combustion gas which pressurizes the chamber in which the extinguishing agent is present and, consequently, the delivery of the extinguishing agent to the fire zone. These fire extinguishers with pyrotechnic gas generator are relatively powerful and can overcome some of the disadvantages of fire extinguishers permanent pressurization.

In particular document is known DE202006002892 an extinguisher comprising a pyrotechnic gas generator having an architecture relatively close to the permanent pressurizing extinguishers using a pressurized gas cylinder. In this document, the gas generator is actuated by a manual striker located at one end of the tank and communicates with the loading of the extinguishing agent via a first dip tube. A second plunger tube is connected to the outlet port and provides delivery of the extinguishing agent to the outlet port. A lance equipped with a trigger communicates with the outlet orifice and allows the extinguishing agent to be delivered into the external medium following actuation by a user.

The extinguisher of the document DE202006002892 has certain advantages but has however a structure that it would be desirable to be able to simplify in particular to reduce the cost of manufacturing such extinguisher. Furthermore, the delivery rate of the extinguishing agent is not always optimal in this type of extinguisher. Document is also known RU 2 085 235 C1 a simplified fire extinguisher comprising a pyrotechnic gas generator.

There is therefore a need for fire extinguishers having a simplified structure and a reduced manufacturing cost.

There is still a need for fire extinguishers having a delivery rate of the optimized extinguishing agent.

Object and summary of the invention

For this purpose, the invention proposes, according to a first aspect, a fire extinguisher comprising a body extending along a longitudinal axis and defining a storage chamber in which a loading of an extinguishing agent is present and a pressurizing chamber comprising a pyrotechnic gas generator, the pressurizing chamber being separated from the storage chamber by a perforated wall configured to put in communication an output of the pyrotechnic gas generator with the chamber of storage, the perforated wall defining a bottom of the storage chamber, the extinguisher comprising a discharge channel configured to deliver the extinguishing agent outside the extinguisher during the actuation of the pyrotechnic gas generator , said evacuation channel opening into the storage chamber through an opening positioned at a distance from the perforated wall, measured along the longitudinal axis of the body, less than or equal to half the length of the storage chamber.

The pyrotechnic gas generator is configured to produce combustion gas flowing to the storage chamber through the outlet of said gas generator and the perforated wall to pressurize the storage chamber. The evacuation channel is, in turn, configured to allow the delivery of extinguishing agent in the environment outside the extinguisher following the pressurization of the storage chamber by the combustion gas.

The extinguisher according to the present invention has a particular arrangement in which there is on the one hand separation between the compartment comprising the gas generator and the compartment comprising the extinguishing agent and on the other hand positioning of the evacuation channel relatively close to the bottom of the storage chamber. The inventors have found that this particular arrangement advantageously allows to have a powerful fire extinguisher allowing the delivery of the majority or substantially all of the mass of the loading of the extinguishing agent while having a simplified structure in which the implementation of dip tubes in the storage chamber is rendered superfluous. As a result, the invention provides an effective extinguisher having a manufacturing cost significantly reduced compared with the extinguishers described in DE202006002892 .

In an exemplary embodiment, the fire extinguisher may further comprise a first shutter sealing the discharge channel, said first shutter being configured to allow the exit of the extinguishing agent outside the fire extinguisher through the discharge channel when the pressure in the storage chamber exceeds a predefined value.

As mentioned above, the delivery rate of the extinguishing agent may not always be optimal when an extinguisher as taught in the document DE202006002892 is implemented. The inventors have found that the problem that can be encountered by a fire extinguisher of this type using manual actuation is that, at the moment when the user actuates the opening of the outlet orifice, the pressure inside the reservoir may have significantly decreased. Indeed, the gases generated by a pyrotechnic gas generator are hot and the pressurizing effect of the tank is therefore more temporary, because of the cooling of the gases, than that provided by a gas cartridge generating cold gases. It is therefore advantageous not to postpone the expulsion of the extinguishing agent due to the presence of a manual actuation as may be the case in the architecture of the document DE202006002892 . Thus, the above configuration implementing the first shutter advantageously makes it possible to optimize the flow rate of extinguishing agent delivered by the extinguisher since, as soon as a predetermined pressure threshold is reached in the storage chamber, the first shutter automatically allows (ie without requiring actuation by a user) the delivery of extinguishing agent outside the fire extinguisher. Such a configuration advantageously makes it possible to best use the overpressure generated by the gas generator to distribute the extinguishing agent and avoids the problem of actuation by a user that can be carried out at a time when the overpressure in the reservoir has already significantly decreased. Such a configuration thus advantageously makes it possible to make best use of the advantages provided by a pyrotechnic gas generator with respect to a gas cartridge, advantages related to the ability to generate the gas according to a time profile of gas. adapted flow rate unlike a gas cartridge generating a drastically decreasing flow profile.

In an exemplary embodiment, the perforated wall may comprise at least one perforation and the extinguisher may further comprise a second shutter sealing said at least one perforation, said second shutter being configured to allow, under the effect of the pressure of a combustion gas produced by the gas generator, the flow of said gas to the storage chamber through said at least one perforation.

The presence of the second shutter is advantageous in order to isolate and protect the gas generator by preventing pollution of said generator by the extinguishing agent.

In an exemplary embodiment, the opening may be located on a side wall of the body.

In an exemplary embodiment, the distance between the opening and the perforated wall may be less than or equal to one quarter of the length of the storage chamber.

Such a configuration advantageously makes it possible to further increase the fraction of the loading of the extinguishing agent that can be distributed by the extinguisher during operation.

In an exemplary embodiment, the distance between the opening and the perforated wall may be less than or equal to the internal diameter of the storage chamber.

The diameter of the storage chamber corresponds to the largest transverse dimension of the storage chamber.

Such a configuration advantageously makes it possible to further increase the fraction of the loading of the extinguishing agent that can be distributed by the extinguisher during operation.

Alternatively, the discharge channel may pass through the pressurizing chamber and the opening may be located on the perforated wall. Thus, in an exemplary embodiment of the invention, the opening may be positioned at a zero distance from the perforated wall.

Such a configuration advantageously allows to have a fire extinguisher to deliver a particularly high fraction of the loading of the extinguishing agent.

In particular, the pressurizing chamber may be located between the perforated wall and a bottom wall of the body, the exhaust channel also passing through the bottom wall. Alternatively, the evacuation channel passes through the perforated wall, the pressurizing chamber, and the body sidewall at the pressurizing chamber.

In an exemplary embodiment, the ratio [length of the storage chamber] / [internal diameter of the storage chamber] may be less than or equal to 10.

Such a configuration advantageously makes it possible to further increase the fraction of the loading of the extinguishing agent that can be distributed by the extinguisher during operation.

In an exemplary embodiment, the perforated wall may comprise a plurality of perforations distributed around the longitudinal axis of the body of the fire extinguisher.

In an exemplary embodiment, the extinguishing agent may be in powder form. Alternatively, the extinguishing agent may be in another form, for example in the form of a foam.

In an exemplary embodiment, the gas generator may comprise at least one housing comprising a pyrotechnic charge, said pyrotechnic charge having a through channel.

The presence of such a through channel in the pyrotechnic charge advantageously allows to control the flow of gas generated during the combustion of said load, or even to make this flow rate constant.

In an exemplary embodiment, the gas generator may comprise a plurality of housings each comprising a pyrotechnic charge, said housings being positioned around the longitudinal axis of the body. In addition, the housing can be positioned around an ignition device configured to ignite the pyrotechnic charge present in said housing.

Such configurations advantageously make it possible to have a gas generator having a relatively compact structure.

The present invention also relates to a vehicle equipped with a fire extinguisher as described above.

In particular, the vehicle can be a bus. The extinguisher may in an exemplary embodiment be integrated with a vehicle to allow the extinction of a fire in the engine of said vehicle.

Brief description of the drawings

• la figure 1 représente un exemple d'extincteur selon l'invention,
• la figure 2 représente une coupe longitudinale et partielle de l'extincteur de la figure 1,
• la figure 3 représente un détail de l'extincteur de la figure 1,
• la figure 4 illustre le fonctionnement de l'extincteur de la figure 1,
• la figure 5 représente un autre exemple d'extincteur selon l'invention,
• la figure 6 illustre le fonctionnement de l'extincteur de la figure 5, et
• la figure 7 représente une variante de générateur de gaz pyrotechnique utilisable dans le cadre de l'exemple de la figure 1.

Other characteristics and advantages of the invention will emerge from the following description of particular embodiments of the invention, given by way of non-limiting examples, with reference to the appended drawings, in which:

• the figure 1 represents an example of extinguisher according to the invention,
• the figure 2 represents a longitudinal and partial section of the extinguisher of the figure 1 ,
• the figure 3 represents a detail of the extinguisher of the figure 1 ,
• the figure 4 illustrates the operation of the extinguisher of the figure 1 ,
• the figure 5 represents another example of extinguisher according to the invention,
• the figure 6 illustrates the operation of the extinguisher of the figure 5 , and
• the figure 7 represents a variant of a pyrotechnic gas generator that can be used in the context of the example of the figure 1 .

Detailed description of embodiments

We have shown figure 1 an example of fire extinguisher 1 according to the invention. The extinguisher comprises a body 2 extending along a longitudinal axis X and defining a storage chamber 4 in which a loading (not shown) of an extinguishing agent is present. In the example illustrated, the extinguishing agent is in the form of a powder, this powder may be for example any known powder useful for extinguishing fires of class A, B or C. As mentioned above, the The invention covers the use of an extinguishing agent in other forms such as a foam. It is advantageous that the extinguishing agent is in the form of a loose powder, as it will be detailed below. The body 2 further defines a pressurizing chamber 5 comprising a pyrotechnic gas generator. The pressurizing chamber 5 is separated from the storage chamber 4 by a perforated wall 7 configured to connect an output of the pyrotechnic gas generator with the storage chamber 4. The body 2 has, in the illustrated example, a symmetrical form of revolution, here cylindrical. Of course, the invention is not limited to such shapes for the body 2. The body 2 has a side wall 2a extending along the longitudinal axis X of the body 2 and surrounding the storage chamber 4. The side wall 2a of the body further surrounds the pressurizing chamber 5. The body 2 further comprises a bottom wall 2b and an upper wall 2c. The bottom wall 2b and the upper wall 2c delimit longitudinally the body 2. The pressurizing chamber 5 is located between the perforated wall 7 and the bottom wall 2b of the body 2. The storage chamber 4 is located between the upper wall 2c of the body 2 and the perforated wall 7, the latter defining a bottom of the storage chamber 4. In order to improve the quantity of extinguishing agent delivered by the fire extinguisher by promoting the creation of a fluidized bed upon actuation of the pyrotechnic gas generator, the ratio l _s / D where D is the internal diameter of the storage chamber 4 and _s the length of the storage chamber measured along the longitudinal axis X can advantageously be less than or equal to 10, for example less than or equal to 6, for example less than or equal to 5. This ratio l _s / D can be greater than or equal to 3. The length l _s of the storage chamber 4 can for example, be between 45 cm and 90 cm. The internal diameter D of the storage chamber 4 may for example be between 10 cm and 20 cm, for example be substantially equal to 15 cm.

The figure 2 represents a partial section along the longitudinal axis X of the extinguisher 1 of the figure 1 . The figure 2 illustrates in greater detail the arrangement of the pressurizing chamber 5. As illustrated, the pressurizing chamber 5 comprises a pyrotechnic gas generator 20 which is configured to produce a combustion gas in order to pressurize the chamber of combustion. storage 4. The gas generator 20 comprises, in the illustrated example, a plurality of housings 22, each of these housings 22 having a loading The gas generator 20 further comprises an ignition device 25 configured to ignite the pyrotechnic charge 23 present in the housings 22. The gas generator 20 may be electrically tripped by application of an electric current across the terminals of the gas generator 20. the initiator (as represented on the figure 2 ) or mechanical (triggering by percussion). In the case of a mechanical trigger, a striker strikes the ignition device. In all cases, the initiation of the ignition device 25 leads to the combustion of the central load 27, which is in the example illustrated in the form of stacked blocks, thereby engaging the combustion of the pyrotechnic charges 23 and the release of the gases from combustion. It is not beyond the scope of the present invention when the gas generator 20 comprises a single housing provided with its pyrotechnic charge.

The pyrotechnic charges 23 may be in the form of monolithic blocks possibly having at least one opening channel, as will be detailed below. Alternatively, the pyrotechnic charges 23 may be in the form of a granular material. It is of course possible to have in the same gas generator a first part of the pyrotechnic charges which are in the form of monolithic blocks and a second part of the pyrotechnic charges which are in the form of a granular material.

The pyrotechnic charges 23 used in the gas generator 20 of the fire extinguisher 1 may have the same composition as the pyrotechnic charges typically used in gas generators for airbags. Of course, the pyrotechnic charges 23 have dimensions adapted to the intended operating time (ie greater than those of the pyrotechnic charges used in gas generators for airbags). Pyrotechnic compositions that can be used in the gas generator of the extinguisher according to the invention have been described in particular in the following documents: US 5,608,183 , US 6,143,102 , FR 2 975 097 , FR 2 964 656 , FR 2 950 624 , FR 2 915 746 , FR 2 902 783 , FR 2,899,227 , FR 2,892,117 , FR 2 891 822 , FR 2 866 022 , FR 2,772,370 and FR 2,714,374 . The gas generator may for example comprise at least five pyrotechnic charges 23, for example at least ten pyrotechnic charges, for example at least twenty pyrotechnic charges.

The extinguisher 1 furthermore has a discharge channel 12 configured to deliver the extinguishing agent outside the extinguisher 1 when the pyrotechnic gas generator 20 is actuated. In the example illustrated in FIG. figure 2 , the channel 12 passes through the pressurizing chamber 5 and the perforated wall 7 and opens directly onto the storage chamber 4. Thus, the channel 12 opens onto the storage chamber 4 through an opening 12a located on the wall perforated 7. In this case, the opening 12a is positioned at a zero distance from the perforated wall therefore necessarily less than or equal to half the length of the storage chamber. The channel 12 also passes through the bottom wall 2b of the body 2. The extinguisher 1 is configured to deliver the extinguishing agent when the pyrotechnic gas generator is actuated through an outlet orifice 10 situated in the bottom wall 2b of the body. So, in the example shown in the figure 2 , the channel 12 has a first end opening on the storage chamber 4 constituted by the opening 12a and a second end emerging outside the extinguisher 1 constituted by the outlet orifice 10. The channel 12 extends in the illustrated example along the longitudinal axis of the body X. The channel 12 may, for example, have a diameter D ₁ (greater transverse dimension) of between 20 mm and 40 mm. In a variant not shown, it is possible that the outlet orifice is present in the side wall of the body at the level of the pressurizing chamber and that this orifice communicates in the same way with the storage chamber via a channel passing through the pressurizing chamber and the perforated wall and opening directly to the storage chamber.

The extinguisher 1 further comprises a first shutter 15 sealingly closing the discharge channel 12, the first shutter 15 being configured to allow the exit of the extinguishing agent outside the extinguisher 1 through of the channel 12 when the pressure in the storage chamber 4 exceeds a predefined value. In other words, the first shutter 15 is configured to prevent, when in a first configuration, the exit of the extinguishing agent outside the extinguisher 1, the first shutter 15 is in position. further configured to go into a second configuration when the pressure in the storage chamber 4 exceeds a preset value, this second configuration of the first shutter 15 allowing the exit of the extinguishing agent outside the extinguisher 1. The The first shutter 15 may, for example, be in the form of a membrane configured to yield when the pressure in the storage chamber 4 exceeds a predefined value. In this case, the first shutter 15 may, for example, be an aluminum or alloy membrane of Inconel® type. Alternatively, the first shutter 15 may be configured to move without yielding when the pressure in the storage chamber 4 exceeds a predefined value, thereby allowing the extinguishing agent to exit outside the extinguisher at the same time. through the discharge channel 12 and the outlet port 10. In this case, the first shutter 15 may for example be in the form of a valve, for example in the form of a spring valve. As explained above, the presence of the first shutter is advantageous in order to overcome the need for a user to actuate the delivery of extinguishing agent outside the fire extinguisher. This advantageously makes it possible to optimize the flow rate of extinguishing agent delivered by the fire extinguisher.

It is not beyond the scope of the present invention when the extinguisher comprises a plurality of discharge channels, all or part of these channels being or not provided with a first shutter as described above. It is also beyond the scope of the invention when the fire extinguisher is devoid of such a first shutter. In the latter case, the delivery of extinguishing agent to the outside of the fire extinguisher is actuated by a user.

We have shown figure 3 in more detail the perforated wall 7. The perforated wall 7 separates the pyrotechnic gas generator from the extinguishing agent present in the storage chamber. The perforated wall 7 is configured to communicate an output of the pyrotechnic gas generator with the storage chamber. As illustrated, the perforated wall 7 may, for example, be in the form of a plate provided with a plurality of perforations 8 configured to allow the flow of a combustion gas produced by the pyrotechnic gas generator to the chamber storage. The perforated wall 7 has a plurality of perforations 8 distributed around the longitudinal axis X of the body 2 of extinguisher 1. The flow direction of the combustion gas through the perforated wall is, in the illustrated example, substantially parallel to the longitudinal axis of the body. In an exemplary embodiment, the perforations 8 act as a nozzle for the gas generator. The perforated wall 7 extends transversely, for example perpendicularly, with respect to the longitudinal axis of the body.

All or part of the perforations 8 of the perforated wall 7 may before the first use of the fire extinguisher 1 be closed sealingly by a second shutter configured to allow, under the effect of the pressure of the combustion gas produced by the generator of gas, the flow of said gas to the storage chamber through the perforations. The second shutter may, for example, be in the form of a membrane which may be located in the storage chamber and cover the perforated wall 7 or which may be located in the pressurizing chamber. This membrane may be in contact with the perforated wall 7. The membrane may for example be formed of a plastic material such as poly (ethylene terephthalate) or a self-adhesive metal film such as an aluminum film or of tin in order to obtain a shearing operation during pressurization by the pyrotechnic gas generator. The membrane may advantageously be glued to the perforated wall 7. The second shutter may be able to yield under the effect of the pressure of the combustion gas produced by the gas generator in order to allow the flow of said gas to the storage chamber . The presence of the second shutter is advantageous in order to isolate and protect the gas generator by preventing pollution of said generator by the extinguishing agent and allows better control of the ignition of the pyrotechnic charges. Of course, it is not beyond the scope of the present invention when the extinguisher is devoid of such a second shutter.

Thus, as illustrated in particular Figures 1 to 3 , the fire extinguisher 1 is devoid of a dip tube extending in the loading of the extinguishing agent and to ensure the transport of the extinguishing agent to the outlet orifice. In the same way, the fire extinguisher 1 is devoid of a dip tube extending in the loading of the extinguishing agent and for transporting the combustion gas produced by the gas generator in the loading of the agent. extinction. So, the invention advantageously provides fire extinguishers with a reduced number of components compared to the prior art and thus have structures lighter and less expensive with an efficiency at least equal.

The operation of fire extinguisher 1 described in connection with Figures 1 to 3 will now be described.

The actuation of the pyrotechnic gas generator makes it possible to ensure the combustion of one or more pyrotechnic charges in order to generate a combustion gas. Under the effect of the pressure of this combustion gas, the second shutter gives way to allow the combustion gas to flow through the perforated walls to the storage chamber and to come into contact with the agent. extinction. The combustion gas thus makes it possible to pressurize the storage chamber. In the storage chamber, the loading of the extinguishing agent can, as mentioned above, be in the form of a powder. This powder may advantageously have an apparent density of between 40% and 55% of the theoretical density. Such values for the apparent density of the powder advantageously make it possible, during the introduction of the combustion gas into the storage chamber, to create a fluidized bed which makes it possible to promote the delivery of the extinguishing agent outside the combustion chamber. 'extinguisher. Once a predefined value has been reached for the pressure in the storage chamber, the first shutter passes into a second configuration allowing the exit of the extinguishing agent outside the extinguisher through the evacuation channel and the outlet port. The predefined value of the pressure in the storage chamber from which the first shutter passes in the second configuration may be greater than or equal to 20 bars, or even 40 bars. The duration during which the extinguishing agent is delivered outside the extinguisher may, for example, be greater than or equal to 1 second, or even 5 seconds, or even 10 seconds. In an advantageous variant, the gas generator continues to operate after the passage of the first shutter in the second configuration. This advantageously makes it possible to increase the fraction of extinguishing agent delivered outside the fire extinguisher. Alternatively, the gas generator stops operating once the first shutter has passed into the second configuration. As mentioned above, the illustrated arrangement advantageously avoids clogging of the outlet orifice with the extinguishing agent and thus allows the delivery of a significant fraction of the extinguishing agent outside the 'extinguisher. During operation, the fire extinguisher may be horizontal or vertical and, for example, be mounted on a vehicle. We have shown figure 4 very schematically the operation of the extinguisher of the figure 1 . The introduction of the combustion gas into the storage chamber 4 is materialized at the figure 4 by the arrow I and the exit of the extinguishing agent outside the extinguisher 1 by the arrow S. In the illustrated example, the direction of introduction of the combustion gas into the storage chamber and the direction of exit of the extinguishing agent outside the extinguisher are each substantially parallel to the longitudinal axis X of the body 2.

We have shown figure 5 a variant extinguisher 1 'according to the invention. In the same way as for extinguisher 1 shown in figure 1 , extinguisher 1 'comprises a body 2' defining a storage chamber 4 'in which a loading of extinguishing agent is present and a pressurizing chamber 5' comprising a pyrotechnic gas generator. The pressurizing chamber 5 'is separated from the storage chamber 4' by a perforated wall 7 'configured to place an output of the pyrotechnic gas generator in communication with the storage chamber 4'. In the same way as for the example of figure 1 , the perforated wall 7 'has a plurality of perforations 8' distributed around the longitudinal axis X 'of the body 2' of the fire extinguisher 1 '. Unlike the example shown in figure 1 , the discharge channel 12 'passes through a side wall 2'a of the body. The discharge channel 12 'opens out onto the storage chamber 4' through an opening 12 'positioned at a distance d from the perforated wall 7' less than or equal to half the length l _s of the chamber storage, or even a quarter of this length, or even less than or equal to the internal diameter D of the storage chamber. As illustrated in Figures 5 and 6 the distance d corresponds to the distance separating the center of the opening 12'a from the perforated wall 7 '. In the example shown in Figures 5 and 6 , the channel 12 'has a first end opening on the storage chamber 4' constituted by the opening 12'a and a second end opening outside the fire extinguisher 1 constituted by the outlet orifice 10 '. As in the case of the embodiment of the figure 1 , extinguisher 1 'may or may not include a first shutter and / or a second shutter.

The operation of the fire extinguisher 1 'illustrated in figure 5 has been represented very schematically in the figure 6 . The introduction of the combustion gas into the storage chamber 4 'is materialized at the figure 6 by the arrow I and the exit of the extinguishing agent outside the extinguisher 1 'by the arrow S. In the illustrated example, the direction of introduction of the combustion gas into the storage chamber is substantially parallel to the longitudinal axis X 'of the body 2' and the exit direction S of the extinguishing agent outside the extinguisher is substantially perpendicular to the longitudinal axis X 'of the body 2'.

We have shown figure 7 a pyrotechnic gas generator variant 20 'that can be used in the context of the example of the figure 1 . The gas generator 20 'comprises a plurality of housings 22 each comprising a pyrotechnic charge 23, the housings 22 being positioned around the longitudinal axis of the body of the extinguisher. As illustrated, the housings 22 extend radially (perpendicular to the longitudinal axis of the body). The example shown in figure 7 comprises a first group of housing superimposed on a second group of housing, the housing of the first group being present at a first height in the body and the housing of the second group being present at a second height in the body different from the first height. Of course, it is not beyond the scope of the invention when the pyrotechnic gas generator comprises a single group of housings positioned around the longitudinal axis of the body of the fire extinguisher, said housings being all present at the same height in the body. In the example of the figure 7 the housings 22 are positioned around an ignition device 25 configured to ignite the pyrotechnic charges 23 present in said housing. The ignition device 25 has radial orifices, each orifice being located opposite a pyrotechnic charge 23. The ignition device 25 is as shown in FIG. figure 7 present in a central portion of the pyrotechnic gas generator 20 '. In addition, all or part of the pyrotechnic charges 23 may as illustrated in FIG. figure 7 , present a channel opening 24. Each channel 24 opens at two opposite ends of a pyrotechnic charge 23. The presence of such a through channel in the pyrotechnic charge advantageously allows to control the flow of gas generated during the combustion of said pyrotechnic charge, even to make this flow constant. The gas generator 20 'shown in FIG. figure 7 advantageously has a relatively compact structure and a small footprint. Of course, one can alternatively overcome the presence of the channel 12 and integrate a pyrotechnic gas generator of this type in the fire extinguisher of the type illustrated in FIG. figure 5 .

The expression "understood between ... and ..." or "from ... to ..." must be understood as including the boundaries.

Claims (15)

1. A fire extinguisher (1; 1') comprising a body (2; 2') extending along a longitudinal axis (X; X') and defining a storage chamber (4; 4') in which a load of an extinguishing agent is present, and also a pressurizing chamber (5; 5') comprising a pyrotechnic gas generator (20; 20'), the pressurizing chamber (5; 5') being separated from the storage chamber (4; 4') by a perforated wall (7; 7') configured to put an outlet of the pyrotechnic gas generator (20; 20') into communication with the storage chamber (4; 4'), the perforated wall (7; 7') defining an end of the storage chamber (4; 4'), the extinguisher having a discharge channel (12; 12') configured to deliver the extinguishing agent to the outside of the extinguisher (1; 1') during actuation of the pyrotechnic gas generator (20; 20');
   the extinguisher being characterized in that said discharge channel (12; 12') opens out into the storage chamber (4; 4') through an opening (12a; 12'a) positioned at a distance (d) from the perforated wall (7; 7'), as measured along the longitudinal axis of the body, that is less than or equal to half the length (ℓ_s) of the storage chamber (4; 4').
2. An extinguisher according to claim 1, further comprising a first shutter (15) shutting the discharge channel (12) in sealed manner, said first shutter (15) being configured to enable the extinguishing agent to exit to the outside of the extinguisher through the discharge channel (12) when the pressure in the storage chamber (4) exceeds a predefined value.
3. An extinguisher according to claim 1 or claim 2, wherein the perforated wall (7) includes at least one perforation (8) and the extinguisher also includes a second shutter shutting said at least one perforation (8) in sealed manner, said second shutter being configured to act, under the effect of the pressure of a combustion gas produced by the gas generator, to enable said gas to flow into the storage chamber (4) through said at least one perforation (8).
4. An extinguisher according to any one of claims 1 to 3, wherein the discharge channel (12) passes through the pressurizing chamber (5) and the opening (12a) is situated in the perforated wall (7).
5. An extinguisher according to claim 4, wherein the pressurizing chamber (5) is situated between the perforated wall (7) and an end wall (2b) of the body, the discharge channel (12) also passing through the end wall (2b) .
6. An extinguisher according to any one of claims 1 to 3, wherein the opening (12'a) is situated in a side wall (2'a) of the body (2').
7. An extinguisher according to any one of claims 1 to 6, wherein the distance (d) between the opening (12a; 12'a) and the perforated wall (7; 7') is less than or equal to one-fourth of the length (ℓs) of the storage chamber (4; 4').
8. An extinguisher according to any one of claims 1 to 7, wherein the distance (d) between the opening (12a; 12'a) and the perforated wall (7; 7') is less than or equal to the inside diameter (D) of the storage chamber (4; 4').
9. An extinguisher according to any one of claims 1 to 8, wherein the ratio [length (ℓs) of the storage chamber (4; 4')]/[inside diameter (D) of the storage chamber (4; 4')] is less than or equal to 10.
10. An extinguisher according to any one of claims 1 and 9, wherein the perforated wall (7) presents a plurality of perforations (8) distributed around the longitudinal axis (X) of the extinguisher.
11. An extinguisher according to any one of claims 1 to 10, wherein the extinguishing agent is in powder form.
12. An extinguisher according to any one of claims 1 to 11, wherein the gas generator (20') includes at least one housing (22) containing a pyrotechnic charge (23), said pyrotechnic charge (23) presenting a through channel (24) .
13. An extinguisher according to any one of claims 1 to 12, wherein the gas generator (20') includes a plurality of housings (22), each containing a pyrotechnic charge (23), said housings being positioned around the longitudinal axis (X) of the body.
14. An extinguisher according to claim 13, wherein the housings (22) are positioned around an igniter device (25) configured to ignite the pyrotechnic charges (23) present in said housings (22).
15. A vehicle fitted with an extinguisher (1; 1') according to any one of claims 1 to 14.

Images