EP0545764B1 - Locking device for a casing containing pyrotechnical material - Google Patents

Locking device for a casing containing pyrotechnical material Download PDF

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Publication number
EP0545764B1
EP0545764B1 EP92403127A EP92403127A EP0545764B1 EP 0545764 B1 EP0545764 B1 EP 0545764B1 EP 92403127 A EP92403127 A EP 92403127A EP 92403127 A EP92403127 A EP 92403127A EP 0545764 B1 EP0545764 B1 EP 0545764B1
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EP
European Patent Office
Prior art keywords
pressure
casing
chamber
locking means
pyrotechnic materials
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP92403127A
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German (de)
French (fr)
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EP0545764A1 (en
Inventor
Bruno Boissiere
Michel Bossus
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Thomson Brandt Armements SA
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Thomson Brandt Armements SA
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Publication date
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Publication of EP0545764A1 publication Critical patent/EP0545764A1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B39/00—Packaging or storage of ammunition or explosive charges; Safety features thereof; Cartridge belts or bags
    • F42B39/20—Packages or ammunition having valves for pressure-equalising; Packages or ammunition having plugs for pressure release, e.g. meltable ; Blow-out panels; Venting arrangements

Definitions

  • the present invention relates to a device for locking an envelope containing pyrotechnic materials. It applies, for example, to reducing the vulnerability of thrusters to accidental environments.
  • the first consists of the rise in temperature of a propellant, for example, up to the temperature of self-ignition of pyrotechnic materials, of propellant generally.
  • the time between the start of the thermal attack and the pyrotechnic event therefore depends on the auto-ignition temperature of the propellant but also on the structural elements surrounding the charge such as ferrules, thermal protection or inhibitors for example.
  • the invulnerability specifications impose a minimum delay, for example 3 to 5 minutes for this self-ignition.
  • the second phase corresponds to the pyrotechnic event itself.
  • the detonation, as well as the deflagration not being admitted, failing to know how to avoid combustion, the pyrotechnic event of lower gravity is sought; this event is combustion without propulsion or projection.
  • the rise in pressure of the gases generated by the auto-ignition of the fuel, for example propellant leads to the pneumatic explosion of the casing of the propellant, therefore to a deflagration.
  • this climb pressure is indeed very difficult to avoid because the envelope thereof is designed to withstand high pressure. This pressure is generally the maximum operating pressure increased by a safety factor, it can reach several hundred bars.
  • the object of the invention is to overcome the aforementioned drawbacks by providing in particular a double locking system which depends on the internal pressure of the envelope.
  • the main advantages of the invention are that it makes it possible to distinguish normal ignition from accidental ignition, that it makes it possible to effect the confinement of the casing of the propellant only when the normal ignition is activated, thus allowing effective protection against deflagrations, especially during phases such as storage, handling or transport for example, that it is simple to implement and that it is inexpensive.
  • FIG. 1 presents a sectional view of an envelope 1 containing pyrotechnic materials 2, the opening of which is closed by a closing element 3.
  • the pyrotechnic materials 2 may be those of a propellant, constituted for example by a block of propellant, and the closure element, one end of a rocket for example.
  • Ignition means 4 integral for example with the closing element 3 are in position to ignite the pyrotechnic materials 2. This ignition is caused by the activation of the ignition means 4, this activation can for example be controlled by a electrical signal. These ignite the pyrotechnic materials 2 by giving off a hot gas, at a temperature generally of about 2000 ° C.
  • the casing 1 is held integral with the closure element 3 by at least first locking means 5, 6.
  • These means 5, 6, may for example be screws.
  • P o the locking means 5, 6 no longer ensure the maintenance of the envelope 1 on the closing element 3, by breaking for example, this which allows the envelope to be opened in the event of accidental overpressure inside it.
  • the locking device comprises second locking means 7, 8 according to the invention.
  • the envelope 1 is mainly held integral with the closure element 3 by these second locking means 7, 8.
  • they keep the envelope 1 secured to the closure element 3 only if the ignition means 4 have been activated, these second locking means 7, 8 allowing the envelope 1 to remain integral with the closure element 3 with internal pressures greater than the given pressure P o , so as to withstand the overpressures generated by the combustion of the pyrotechnic materials 2.
  • These second locking means 7, 8 may for example consist of pistons integral with the element closure 3 being introduced into the notches of the casing 1 at the time of activation of the ignition means 4.
  • second locking means must have dimensions making it possible to hold the internal pressures of the casing 1, these these can reach for example several hundred bars.
  • the first locking means 5, 6 can remain active when the second means 7, 8 are active; nevertheless, their holding role is negligible vis-à-vis the second locking means 7, 8.
  • FIG. 2a details a possible embodiment of a device according to the invention.
  • This device is used to close the opening of the envelope 1 on the closing element 3 and to lock this closing.
  • the closing element 3 can for example be a rocket or rocket end, the casing 1 containing pyrotechnic materials 2, for example a block of propellant whose combustion allows the propulsion of the rocket or the rocket.
  • the first locking means are for example constituted by screws, three for example, two of which 5, 6, are shown, which hold the casing 1 secured to the closure element 3. For this, the screws pass through holes made at the end of the casing 1 in contact with the closing element 3, the screws 5, 6, being screwed into tapped holes made in this closing element 3.
  • the second locking means are constituted for example by four pistons of which only one 9 is shown in section in FIG. 2a, of two closure elements 14, 15 of which only one is shown in section in FIG. 2a, springs for holding the pistons and closure elements, two of which 16, 27 are shown in section in FIG. 2a, these elements being integral with the closing element 3.
  • These second means of closure are further supplemented by a groove for receiving the pistons produced in the envelope 1.
  • the groove 13, for receiving the piston 9, is shown in FIG. 2a.
  • the closure elements 14, 15 may for example be balls.
  • Figure 2b shows a sectional view along the axis BB 'of Figure 2a, the envelope and the closure element being for example symmetrical in revolution.
  • This view shows only the position of the four pistons 9, 10, 11, 12 and the two balls 14, 15 of the device as well as the position of the axis AA ′ in the section plane of FIG. 2a, FIG. 2a itself being a sectional view along the axis AA ′ as shown in FIG. 2b and seen along the arrow F.
  • the operation of the second locking means is controlled by the ignition means generally constituted by a heating element 17, an electric igniter for example, and by a small charge 18 with a short combustion time located in a chamber 19 internal to the closing element 3 and hermetically closed by a partition 20. This partition lets the end of the heating element pass 17 outside the chamber 19 in order to connect the latter for example to an electrical connection 21.
  • an electrical activation signal is transmitted to the heating element 17 via the electrical connection 21.
  • the heating element 17 emits hot gases and ignites the small charge 18 with a short combustion time.
  • the pressure generated by its combustion causes the shearing of flanges 25 integral with the pistons 9 and pushes the pistons 9 into the receiving grooves 13, the gases passing through conduits 22 connecting the pistons 9 to the chamber 19.
  • the flanges 25 prevent the pistons to occupy the receiving grooves 13 under the action of the springs as long as the combustion of small load 18 did not take place, that is to say before the normal operation of the propellant.
  • the balls 14, 15 allow the gases to pass via conduits 23, 24 which will ignite the charge of the propellant 2, thanks to their high temperature, 2000 ° C for example.
  • the conduit 23 is connected to the chamber 19 and the conduit 24 is connected to the loading of the propellant 2, the ball 14 closing the passage between these two conduits as long as it is not displaced by the gases from the chamber 19.
  • the closed position of the ball is maintained by a spring 27.
  • the ball does not move and closes the passage.
  • the screws 5, 6 must withstand, for example, transport or carrying environments.
  • the device according to the invention of Figures 2a and 2b it comprises among other elements four pistons, two balls and three screws, but it appears that these quantities may vary depending on the applications and the size materials in particular.
  • Figures 3a and 3b show another possible embodiment of the device according to the invention.
  • the difference with the previous mode is that there are no more pistons.
  • Figure 3b is a sectional view of Figure 3a along the axis DD 'and Figure 3a is a sectional view along the axis CC' of Figure 3b.
  • the ignition means 17, 18, 19 are constituted in the same way as in the embodiment of FIG. 2a.
  • the balls 14, 15 and the springs 27 for holding the latter are arranged differently.
  • the pressure generated by the combustion of the small load 18 causes a thin tube 31 situated between the envelope 1 and the part of the closing element 3 to inflate. in the envelope and containing the ignition means 17, 18, 19.
  • This ring is placed between the tube 31 and the envelope 1. These pieces are pressed against the envelope 1 in the groove 33, and thus make the separation of the envelope 1 from the closure element 3 impossible because the thin tube 31 undergoes permanent deformation.
  • the thin tube 31 having been inflated, the gases coming from the chamber 19 can lift the balls 14, 15 via a conduit 35 and go to ignite the main charge 2 via a conduit not shown.
  • the passage is closed by the latter between the conduits 35 in contact with the chamber 19 after swelling of the thin tube 31 and the unrepresented conduits connected to the main load 2 of a propellant for example.
  • the second locking means therefore consist of the balls 14, 15 their retaining springs 27, the thin tube 31, the fragmentable ring 32 and the receiving grooves 33, 34 of the fragments of the ring 32.
  • the first locking means always consist, for example, of screws 5, 6.

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  • General Engineering & Computer Science (AREA)
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Description

La présente invention concerne un dispositif de verrouillage d'une enveloppe contenant des matières pyrotechniques. Elle s'applique par exemple à la réduction de la vulnérabilité de propulseurs aux environnements accidentels .The present invention relates to a device for locking an envelope containing pyrotechnic materials. It applies, for example, to reducing the vulnerability of thrusters to accidental environments.

Deux types d'agression mettent en cause la sécurité de stockage et d'emploi de produits contenant des charges pyrotechniques, en particulier des propulseurs, d'une part les agressions dues à des échauffements, d'autre part les agressions de type mécanique.Two types of attack call into question the safety of storage and use of products containing pyrotechnic charges, in particular propellants, on the one hand attacks due to overheating, on the other hand attacks of a mechanical type.

Dans les agressions dues à des échauffements, lents ou rapides, deux phases peuvent être distinguées. La première est constituée par la montée en température d'un propulseur par exemple, jusqu'à la température d'auto-inflammation des matières pyrotechniques, du propergol généralement. Le délai entre le début de l'agression thermique et l'évènement pyrotechnique dépend donc de la température d'auto-inflammation du propergol mais aussi des éléments de structure entourant le chargement tels que des viroles, des protections thermiques ou des inhibiteurs par exemple. Généralement les spécifications d'invulnérabilité imposent un délai minimum, par exemple 3 à 5 minutes pour cette auto-inflammation.In attacks due to slow or rapid overheating, two phases can be distinguished. The first consists of the rise in temperature of a propellant, for example, up to the temperature of self-ignition of pyrotechnic materials, of propellant generally. The time between the start of the thermal attack and the pyrotechnic event therefore depends on the auto-ignition temperature of the propellant but also on the structural elements surrounding the charge such as ferrules, thermal protection or inhibitors for example. Generally, the invulnerability specifications impose a minimum delay, for example 3 to 5 minutes for this self-ignition.

La seconde phase correspond à l'évènement pyrotechnique lui-même. La détonation, ainsi que la déflagration n'étant pas admises, à défaut de savoir éviter la combustion, l'évènement pyrotechnique de plus faible gravité est recherché ; cet évènement est la combustion sans propulsion ni projection. Cependant, la montée en pression des gaz générés par l'auto-inflammation du combustible, par exemple du propergol, conduit à l'explosion pneumatique de l'enveloppe du propulseur, donc à une déflagration. Dans un propulseur, cette montée en pression est en effet très difficile à éviter car l'enveloppe de celui-ci est conçue pour résister à une pression élevée. Cette pression étant généralement la pression maximum de fonctionnement majorée d'un coefficient de sécurité, elle peut atteindre plusieurs centaines de bars.The second phase corresponds to the pyrotechnic event itself. The detonation, as well as the deflagration not being admitted, failing to know how to avoid combustion, the pyrotechnic event of lower gravity is sought; this event is combustion without propulsion or projection. However, the rise in pressure of the gases generated by the auto-ignition of the fuel, for example propellant, leads to the pneumatic explosion of the casing of the propellant, therefore to a deflagration. In a propellant, this climb pressure is indeed very difficult to avoid because the envelope thereof is designed to withstand high pressure. This pressure is generally the maximum operating pressure increased by a safety factor, it can reach several hundred bars.

Dans le cas d'agressions de type mécanique, impacts de balles ou de fragments par exemple, il n'est pas possible de compter sur la déformation locale, une ouverture par exemple, provoquée par l'agression mécanique pour empêcher une montée en pression de l'enveloppe si un évènement pyrotechnique se produit. Il faut donc choisir un propergol et des produits pyrotechniques dont l'impact ne provoque pas d'emblée la détonation et faire en sorte que tout évènement pyrotechnique initialisé par l'impact n'entraîne ni déflagration ni propulsion.In the case of mechanical type aggressions, impacts of bullets or fragments for example, it is not possible to count on local deformation, an opening for example, caused by mechanical aggression to prevent a pressure build-up of the envelope if a pyrotechnic event occurs. It is therefore necessary to choose a propellant and pyrotechnic products whose impact does not immediately detonate and ensure that any pyrotechnic event initiated by the impact does not cause deflagration or propulsion.

Pour éviter les évènements évoqués ci-dessus, des procédés de protection dits actifs sont connus de l'homme de l'art. Ces procédés consistent à ouvrir complètement l'enveloppe dès la constatation d'un environnement accidentel. Ils ont l'inconvénient de nécessiter des éléments complémentaires tels que des capteurs, des sources d'énergie ou des actionneurs par exemple, qui accroissent de façon importante la complexité du système. De plus, leur fonctionnement doit être assuré dans l'ensemble des environnements accidentels.To avoid the events mentioned above, so-called active protection methods are known to those skilled in the art. These methods consist in completely opening the envelope as soon as an accidental environment is observed. They have the disadvantage of requiring additional elements such as sensors, energy sources or actuators for example, which significantly increase the complexity of the system. In addition, their operation must be ensured in all accidental environments.

Le but de l'invention est de pallier les inconvénients précités en prévoyant notamment un double système de verrouillage fonction de la pression interne de l'enveloppe.The object of the invention is to overcome the aforementioned drawbacks by providing in particular a double locking system which depends on the internal pressure of the envelope.

Ce problème est résolu par l'objet de la revendication 1.This problem is solved by the subject of claim 1.

L'invention a pour principaux avantages qu'elle permet de distinguer un allumage normal d'un allumage accidentel, qu'elle permet de n'effectuer le confinement de l'enveloppe du propulseur que lors de l'activation de l'allumage normal, permettant ainsi une protection efficace contre les déflagrations, notamment durant des phases telles que le stockage, la manutention ou le transport par exemple, qu'elle est simple à mettre en oeuvre et qu'elle est peu coûteuse.The main advantages of the invention are that it makes it possible to distinguish normal ignition from accidental ignition, that it makes it possible to effect the confinement of the casing of the propellant only when the normal ignition is activated, thus allowing effective protection against deflagrations, especially during phases such as storage, handling or transport for example, that it is simple to implement and that it is inexpensive.

D'autres caractéristiques et avantages de l'invention apparaîtront à l'aide de la description qui suit, faite en regard des dessins annexés qui représentent :

  • la figure 1, une vue en coupe d'un dispositif selon l'invention,
  • les figures 2a, 2b, 3a et 3b, des modes de réalisation possibles de dispositifs selon l'invention.
Other characteristics and advantages of the invention will become apparent with the aid of the description which follows, given with reference to the appended drawings which represent:
  • FIG. 1, a sectional view of a device according to the invention,
  • Figures 2a, 2b, 3a and 3b, possible embodiments of devices according to the invention.

La figure 1 présente une vue en coupe d'une enveloppe 1 contenant des matières pyrotechniques 2 dont l'ouverture est fermée par un élément de fermeture 3. Les matières pyrotechniques 2 peuvent être celles d'un propulseur, constituées par exemple par un bloc de propergol, et l'élément de fermeture, une extrémité d'une roquette par exemple. Des moyens d'inflammation 4 solidaires par exemple de l'élément de fermeture 3 sont en position pour enflammer les matières pyrotechniques 2. Cette inflammation est provoquée par l'activation des moyens d'inflammation 4, cette activation peut être par exemple commandée par un signal électrique. Ceux-ci enflamment les matières pyrotechniques 2 en dégageant un gaz chaud, à une température généralement d'environ 2 000 °C.FIG. 1 presents a sectional view of an envelope 1 containing pyrotechnic materials 2, the opening of which is closed by a closing element 3. The pyrotechnic materials 2 may be those of a propellant, constituted for example by a block of propellant, and the closure element, one end of a rocket for example. Ignition means 4 integral for example with the closing element 3 are in position to ignite the pyrotechnic materials 2. This ignition is caused by the activation of the ignition means 4, this activation can for example be controlled by a electrical signal. These ignite the pyrotechnic materials 2 by giving off a hot gas, at a temperature generally of about 2000 ° C.

Sur la figure 1, selon l'invention, l'enveloppe 1 est maintenue solidaire de l'élément de fermeture 3 par au moins des premiers moyens de verrouillage 5, 6. Ces moyens 5, 6, peuvent être par exemple des vis. En cas de pression interne de l'enveloppe supérieure à une pression Po donnée, les moyens de verrouillage 5, 6 n'assurent plus le maintien de l'enveloppe 1 sur l'élément de fermeture 3, en se cassant par exemple, ce qui permet d'ouvrir l'enveloppe en cas de surpression accidentelle à l'intérieur de celle-ci.In Figure 1, according to the invention, the casing 1 is held integral with the closure element 3 by at least first locking means 5, 6. These means 5, 6, may for example be screws. In case of internal pressure of the envelope greater than a given pressure P o , the locking means 5, 6 no longer ensure the maintenance of the envelope 1 on the closing element 3, by breaking for example, this which allows the envelope to be opened in the event of accidental overpressure inside it.

Le dispositif de verrouillage comporte des seconds moyens de verrouillage 7, 8 selon l'invention. Quand ceux-ci sont actifs, l'enveloppe 1 est principalement maintenue solidaire de l'élément de fermeture 3 par ces seconds moyens de verrouillage 7, 8. Selon l'invention, ils maintiennent l'enveloppe 1 solidaire de l'élément de fermeture 3 uniquement si les moyens d'inflammation 4 ont été activés, ces seconds moyens de verrouillage 7, 8 permettant à l'enveloppe 1 de rester solidaire de l'élément de fermeture 3 avec des pressions internes à celle-ci supérieures à la pression Po donnée, de manière à supporter les surpressions générées par la combustion des matières pyrotechniques 2. Ces seconds moyens de verrouillage 7, 8 peuvent être par exemple constitués de pistons solidaires de l'élément de fermeture 3 s'introduisant dans des encoches de l'enveloppe 1 au moment de l'activation des moyens d'inflammation 4. Ces seconds moyens de verrouillage doivent avoir des dimensions permettant de tenir les pressions internes de l'enveloppe 1, celles-ci peuvent atteindre par exemple plusieurs centaines de bars. Selon l'invention, les premiers moyens de verrouillages 5, 6 peuvent rester actifs quand les seconds moyens 7, 8 sont actifs; néanmoins, leur rôle de maintien est négligeable vis-à-vis des seconds moyens de verrouillage 7, 8.The locking device comprises second locking means 7, 8 according to the invention. When these are active, the envelope 1 is mainly held integral with the closure element 3 by these second locking means 7, 8. According to the invention, they keep the envelope 1 secured to the closure element 3 only if the ignition means 4 have been activated, these second locking means 7, 8 allowing the envelope 1 to remain integral with the closure element 3 with internal pressures greater than the given pressure P o , so as to withstand the overpressures generated by the combustion of the pyrotechnic materials 2. These second locking means 7, 8 may for example consist of pistons integral with the element closure 3 being introduced into the notches of the casing 1 at the time of activation of the ignition means 4. These second locking means must have dimensions making it possible to hold the internal pressures of the casing 1, these these can reach for example several hundred bars. According to the invention, the first locking means 5, 6 can remain active when the second means 7, 8 are active; nevertheless, their holding role is negligible vis-à-vis the second locking means 7, 8.

La figure 2a détaille une réalisation possible d'un dispositif selon l'invention. Ce dispositif sert à fermer l'ouverture de l'enveloppe 1 sur l'élément de fermeture 3 et à verrouiller cette fermeture. L'élément de fermeture 3 peut être par exemple une extrémité de roquette ou fusée, l'enveloppe 1 renfermant des matières pyrotechniques 2, par exemple un bloc de propergol dont la combustion permet la propulsion de la roquette ou de la fusée. Les premiers moyens de verrouillage sont par exemple constitués par des vis, trois par exemple, dont deux 5, 6, sont représentées, qui maintiennent l'enveloppe 1 solidaire de l'élément de fermeture 3. Pour cela, les vis traversent des trous réalisés à l'extrémité de l'enveloppe 1 en contact avec l'élément de fermeture 3, les vis 5, 6, étant vissées dans des trous taraudés réalisés dans cet élément de fermeture 3.Figure 2a details a possible embodiment of a device according to the invention. This device is used to close the opening of the envelope 1 on the closing element 3 and to lock this closing. The closing element 3 can for example be a rocket or rocket end, the casing 1 containing pyrotechnic materials 2, for example a block of propellant whose combustion allows the propulsion of the rocket or the rocket. The first locking means are for example constituted by screws, three for example, two of which 5, 6, are shown, which hold the casing 1 secured to the closure element 3. For this, the screws pass through holes made at the end of the casing 1 in contact with the closing element 3, the screws 5, 6, being screwed into tapped holes made in this closing element 3.

Les seconds moyens de verrouillage sont constitués par exemple par quatre pistons dont un seul 9 est représenté en coupe sur la figure 2a, de deux éléments d'obturation 14, 15 dont un seul est représenté en coupe sur la figure 2a, de ressorts de maintien des pistons et des éléments d'obturation dont deux 16, 27 sont représentés en coupe sur la figure 2a, ces éléments étant solidaires de l'élément de fermeture 3. Ces seconds moyens de fermeture sont complétés par ailleurs par une gorge d'accueil des pistons réalisée dans l'enveloppe 1. La gorge 13, d'accueil du piston 9, est représentée sur la figure 2a. Les éléments d'obturation 14, 15 peuvent être par exemple des billes.The second locking means are constituted for example by four pistons of which only one 9 is shown in section in FIG. 2a, of two closure elements 14, 15 of which only one is shown in section in FIG. 2a, springs for holding the pistons and closure elements, two of which 16, 27 are shown in section in FIG. 2a, these elements being integral with the closing element 3. These second means of closure are further supplemented by a groove for receiving the pistons produced in the envelope 1. The groove 13, for receiving the piston 9, is shown in FIG. 2a. The closure elements 14, 15 may for example be balls.

La figure 2b représente une vue en coupe suivant l'axe BB′ de la figure 2a, l'enveloppe et l'élément de fermeture étant par exemple à symétrie de révolution. Cette vue ne fait apparaître que la position des quatre pistons 9, 10, 11, 12 et des deux billes 14, 15 du dispositif ainsi que la position de l'axe AA′ dans le plan de coupe de la figure 2a, la figure 2a étant elle-même une vue en coupe suivant l'axe AA′ comme représenté sur la figure 2b et vue suivant la flèche F. Le fonctionnement des seconds moyens de verrouillage est commandé par les moyens d'inflammation constitués généralement par un élément chauffant 17, un inflammateur électrique par exemple, et par un petit chargement 18 à faible durée de combustion situé dans une chambre 19 interne à l'élément de fermeture 3 et fermée hermétiquement par une cloison 20. Cette cloison laisse passer l'extrémité de l'élément chauffant 17 à l'extérieur de la chambre 19 afin de relier celui-ci par exemple à une liaison électrique 21.Figure 2b shows a sectional view along the axis BB 'of Figure 2a, the envelope and the closure element being for example symmetrical in revolution. This view shows only the position of the four pistons 9, 10, 11, 12 and the two balls 14, 15 of the device as well as the position of the axis AA ′ in the section plane of FIG. 2a, FIG. 2a itself being a sectional view along the axis AA ′ as shown in FIG. 2b and seen along the arrow F. The operation of the second locking means is controlled by the ignition means generally constituted by a heating element 17, an electric igniter for example, and by a small charge 18 with a short combustion time located in a chamber 19 internal to the closing element 3 and hermetically closed by a partition 20. This partition lets the end of the heating element pass 17 outside the chamber 19 in order to connect the latter for example to an electrical connection 21.

Selon l'invention, lors du fonctionnement normal d'un propulseur d'une roquette ou d'une fusée notamment, un signal électrique d'activation est transmis à l'élément chauffant 17 via la liaison électrique 21. L'élément chauffant 17 émet des gaz chauds et met à feu le petit chargement 18 à faible durée de combustion. La pression générée par sa combustion provoque le cisaillement de collerettes 25 solidaires des pistons 9 et pousse les pistons 9 dans les gorges d'accueil 13, les gaz passant par des conduits 22 reliant les pistons 9 à la chambre 19. Les collerettes 25 empêchent les pistons d'occuper les gorges d'accueil 13 sous l'action des ressorts tant que la combustion de petit chargement 18 n'a pas eu lieu, c'est-à-dire avant le fonctionnement normal du propulseur. Pendant le déplacement des pistons 9, la pression continuant de monter à l'intérieur de la chambre 19, les billes 14, 15 laissent alors passer les gaz via des conduits 23, 24 qui vont allumer le chargement du propulseur 2, grâce à leur haute température, 2000 °C par exemple. Le conduit 23 est relié à la chambre 19 et le conduit 24 est relié au chargement du propulseur 2, la bille 14 obturant le passage entre ces deux conduits tant qu'elle n'est pas déplacée par les gaz issus de la chambre 19. La position d'obturation de la bille est maintenue par un ressort 27. En fait, selon l'invention, tant qu'une partie au moins des pistons 9 n'est pas engagée dans les gorges 13, la bille ne se déplace pas et obture le passage. Ceci est réalisé par exemple de façon qu'à partir d'une valeur de pression donnée dans la chambre 19, les pistons soient en partie engagés dans les gorges 13 et que la force exercée sur les billes 14, 15 par la pression soit inférieure à celle exercée sur les billes 14, 15 par les ressorts 27. Les pistons 9 sont maintenus dans les gorges 13 par les ressorts 16 afin de verrouiller le maintien de l'enveloppe 1 sur l'élément de fermeture 3. Suivant la force exercée par les ressorts 27 de maintient des billes 14, 15, il est possible de régler la pression interne de la chambre 19 à partir de laquelle les billes 14, 15 se lèvent.According to the invention, during normal operation of a rocket or rocket propellant in particular, an electrical activation signal is transmitted to the heating element 17 via the electrical connection 21. The heating element 17 emits hot gases and ignites the small charge 18 with a short combustion time. The pressure generated by its combustion causes the shearing of flanges 25 integral with the pistons 9 and pushes the pistons 9 into the receiving grooves 13, the gases passing through conduits 22 connecting the pistons 9 to the chamber 19. The flanges 25 prevent the pistons to occupy the receiving grooves 13 under the action of the springs as long as the combustion of small load 18 did not take place, that is to say before the normal operation of the propellant. During the displacement of the pistons 9, the pressure continuing to rise inside the chamber 19, the balls 14, 15 then allow the gases to pass via conduits 23, 24 which will ignite the charge of the propellant 2, thanks to their high temperature, 2000 ° C for example. The conduit 23 is connected to the chamber 19 and the conduit 24 is connected to the loading of the propellant 2, the ball 14 closing the passage between these two conduits as long as it is not displaced by the gases from the chamber 19. The closed position of the ball is maintained by a spring 27. In fact, according to the invention, as long as at least part of the pistons 9 is not engaged in the grooves 13, the ball does not move and closes the passage. This is done for example so that from a pressure value given in the chamber 19, the pistons are partly engaged in the grooves 13 and the force exerted on the balls 14, 15 by the pressure is less than that exerted on the balls 14, 15 by the springs 27. The pistons 9 are held in the grooves 13 by the springs 16 in order to lock the maintenance of the casing 1 on the closing element 3. Depending on the force exerted by the springs 27 for holding balls 14, 15, it is possible to adjust the internal pressure of the chamber 19 from which the balls 14, 15 rise.

Si une prise de feu accidentelle du chargement 2 du propulseur a lieu, la pression augmente à l'intérieur de l'enveloppe 1 mais les billes 14, 15 obturant les conduits 23 de liaison avec la chambre 19, elle-même reliée aux pistons par les conduits 22 de liaison, les pistons ne peuvent être déplacés et ne peuvent donc occuper les gorges d'accueil 13 de l'enveloppe 1. Dans ce cas, seuls les premiers moyens de verrouillage 5, 6 maintiennent l'enveloppe 1 solidaire de l'élément de fermeture 3. Ainsi, la pression s'exerçant sur le fond 26 de l'élément de fermeture 3, les vis, constituant par exemple les premiers moyens de verrouillage 5, 6, se cisaillent. L'extrémité de la roquette ou de la fusée, constituant par exemple l'élément de fermeture 3, se désolidarise de l'enveloppe 1 et donc du propulseur 2 de manière à libérer les gaz. Il y a combustion sans propulsion, écartant ainsi tout incident dangereux. Les vis 5, 6 doivent résister par exemple à des environnements de transport ou d'emport. Dans l'exemple de réalisation du dispositif selon l'invention des figures 2a et 2b, celui-ci comporte parmi d'autres éléments quatre pistons, deux billes et trois vis, mais il apparaît que ces quantités peuvent varier suivant les applications et la taille des matériels notamment.If an accidental ignition of the loading of the propellant 2 takes place, the pressure increases inside the casing 1 but the balls 14, 15 closing the conduits 23 connecting with the chamber 19, itself connected to the pistons by the connecting conduits 22, the pistons cannot be moved and therefore cannot occupy the receiving grooves 13 of the envelope 1. In this case, only the first locking means 5, 6 keep the envelope 1 secured to the 'closing element 3. Thus, the pressure exerted on the bottom 26 of the closing element 3, the screws, constituting for example the first locking means 5, 6, shear. The end of the rocket or of the rocket, constituting for example the closing element 3, is detached from the casing 1 and therefore of the propellant 2 so as to release the gases. There is combustion without propulsion, thus ruling out any dangerous incident. The screws 5, 6 must withstand, for example, transport or carrying environments. In the embodiment of the device according to the invention of Figures 2a and 2b, it comprises among other elements four pistons, two balls and three screws, but it appears that these quantities may vary depending on the applications and the size materials in particular.

Les figures 3a et 3b représentent un autre mode de réalisation possible du dispositif selon l'invention. La différence avec le mode précédent est qu'il n'y a plus les pistons. La figure 3b est une vue en coupe de la figure 3a suivant l'axe DD′ et la figure 3a est une vue en coupe suivant l'axe CC′ de la figure 3b. Les moyens d'inflammation 17, 18, 19 sont constitués de la même façon que dans l'exemple de réalisation de la figure 2a. Les billes 14, 15 et les ressorts 27 de maintien de celle-ci sont disposés différemment. Dans l'exemple des figures 3a et 3b, lors du fonctionnement normal du propulseur, la pression générée par la combustion du petit chargement 18 fait gonfler un tube mince 31 situé entre l'enveloppe 1 et la partie de l'élément de fermeture 3 entrant dans l'enveloppe et contenant les moyens d'inflammation 17, 18, 19. Ce gonflement fragmente une bague 32 en, par exemple, 8 morceaux. Cette bague est placée entre le tube 31 et l'enveloppe 1. Ces morceaux se plaquent contre l'enveloppe 1 dans la gorge 33, et rendent ainsi la séparation de l'enveloppe 1 de l'élément de fermeture 3 impossible car le tube mince 31 subit une déformation permanente. Le tube mince 31 ayant été gonflé, les gaz issus de la chambre 19 peuvent soulever les billes 14, 15 via un conduit 35 et aller allumer le chargement principal 2 via un conduit non représenté. Quand les billes 14, 15 ne sont pas soulevées par les gaz, le passage est obturé par celles-ci entre les conduits 35 au contact de la chambre 19 après gonflement du tube mince 31 et les conduits non représentés reliés au chargement principal 2 d'un propulseur par exemple. Dans ce second exemple de réalisation présenté par les figures 3a et 3b, les seconds moyens de verrouillage sont donc constitués par les billes 14, 15 leurs ressorts de maintien 27, le tube mince 31, la bague fragmentable 32 et les gorges d'accueil 33, 34 des fragments de la bague 32. Les premiers moyens de verrouillage sont toujours par exemple constitués de vis 5, 6.Figures 3a and 3b show another possible embodiment of the device according to the invention. The difference with the previous mode is that there are no more pistons. Figure 3b is a sectional view of Figure 3a along the axis DD 'and Figure 3a is a sectional view along the axis CC' of Figure 3b. The ignition means 17, 18, 19 are constituted in the same way as in the embodiment of FIG. 2a. The balls 14, 15 and the springs 27 for holding the latter are arranged differently. In the example of FIGS. 3a and 3b, during normal operation of the propellant, the pressure generated by the combustion of the small load 18 causes a thin tube 31 situated between the envelope 1 and the part of the closing element 3 to inflate. in the envelope and containing the ignition means 17, 18, 19. This swelling fragments a ring 32 into, for example, 8 pieces. This ring is placed between the tube 31 and the envelope 1. These pieces are pressed against the envelope 1 in the groove 33, and thus make the separation of the envelope 1 from the closure element 3 impossible because the thin tube 31 undergoes permanent deformation. The thin tube 31 having been inflated, the gases coming from the chamber 19 can lift the balls 14, 15 via a conduit 35 and go to ignite the main charge 2 via a conduit not shown. When the balls 14, 15 are not lifted by the gases, the passage is closed by the latter between the conduits 35 in contact with the chamber 19 after swelling of the thin tube 31 and the unrepresented conduits connected to the main load 2 of a propellant for example. In this second embodiment presented by FIGS. 3a and 3b, the second locking means therefore consist of the balls 14, 15 their retaining springs 27, the thin tube 31, the fragmentable ring 32 and the receiving grooves 33, 34 of the fragments of the ring 32. The first locking means always consist, for example, of screws 5, 6.

En cas de prise de feu accidentelle du chargement principal 2 constitué par exemple de matières pyrotechniques contenues dans l'enveloppe 1, le fonctionnement est identique à l'exemple précédent décrit par les figures 3a et 3b.In case of accidental ignition of the main load 2 consisting for example of pyrotechnic materials contained in the envelope 1, the operation is identical to the previous example described in Figures 3a and 3b.

Claims (9)

  1. Locking device for a casing (1) containing pyrotechnic materials (2) and ignition means (4) which can be activated to ignite the pyrotechnic materials (2), the ignition means (4) comprising at least one charge (18) contained in a chamber (19), the combustion of which charge increases the pressure inside this chamber (19), the casing (1) having an opening closed by a plugging element (3), characterized in that it includes at least one sealing element (14, 15) held by a spring (27) so as to block a passage (23, 24) of gas between the chamber (19) and the pyrotechnic materials, and locking means (7, 8, 16, 9, 25, 31, 32) permanently deforming under the action of a first pressure so as to ensure that the plugging element (3) is firmly attached to the casing (1), the combustion of the charge (18) in the chamber (19) creating an increase in pressure so that in a first phase the locking means (16, 9, 25, 31, 32) are deformed when the pressure exceeds the first given pressure and so that, in a second phase, the sealing element (14, 15) liberates the passage of hot gas between the chamber (19) and the pyrotechnic materials (2) when the pressure in the chamber (19) becomes higher than a second given pressure, this pressure exerting on the sealing element (14, 15) a force that is greater than and opposed to the holding force of the spring (27), the passage of hot gas towards the pyrotechnic materials igniting the latter.
  2. Device according to Claim 1, characterized in that it further includes other locking means (5, 6) ensuring that the plugging element (3) is firmly attached to the casing (1) up to a pressure threshold (Po) in the casing which is less than the second given pressure.
  3. Device according to either one of the preceding claims, characterized in that the igniting means comprise a heating element (17) activated by an electric signal (21), activation of the heating element (17) bringing about the combustion of the charge (18) in the chamber (19).
  4. Device according to any one of the preceding claims, characterized in that the sealing element (14, 15) is a ball.
  5. Device according to any one of the preceding claims, characterized in that the locking means (7, 8) comprise a piston (9) firmly attached to the plugging element (3) engaging in an accommodating groove (13) in the casing (1) when the pressure in the chamber (19) becomes higher than the first given pressure, the piston being held in the groove (13) by a spring (16).
  6. Device according to Claim 5, characterized in that a flange (25) firmly attached to the piston (9) and holding the latter out of the groove (13) is sheared when the pressure in the chamber (19) becomes higher than the first given pressure.
  7. Device according to any one of Claims 1 to 4, characterized in that the locking means (7, 8) comprise at least one thin tube (31) and a collar which may be divided up into sections (32), situated between the thin tube (31) and the casing (1), portions of the collar (32) engaging in accommodating grooves (33) of the casing (1) when the thin tube (31) expands under the action of the pressure in the chamber (19), this expansion taking place when the pressure becomes higher than the first given pressure, the portions being held in the grooves (33) by the permanent deformation of the thin tube (31).
  8. Device according to any one of the preceding claims, characterized in that the other locking means (5, 6) consist of at least screws screwed both into the casing (1) and the plugging element (3).
  9. Device according to Claim 8, characterized in that the screws (5, 6) are sheared when the pressure inside the casing (1) exceeds the pressure threshold (Po).
EP92403127A 1991-11-29 1992-11-20 Locking device for a casing containing pyrotechnical material Expired - Lifetime EP0545764B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9114818A FR2684439B1 (en) 1991-11-29 1991-11-29 DEVICE FOR LOCKING AN ENVELOPE CONTAINING PYROTECHNIC MATERIALS.
FR9114818 1991-11-29

Publications (2)

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EP0545764A1 EP0545764A1 (en) 1993-06-09
EP0545764B1 true EP0545764B1 (en) 1995-09-13

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EP92403127A Expired - Lifetime EP0545764B1 (en) 1991-11-29 1992-11-20 Locking device for a casing containing pyrotechnical material

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US (1) US5337672A (en)
EP (1) EP0545764B1 (en)
DE (1) DE69204803T2 (en)
FR (1) FR2684439B1 (en)

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US5394803A (en) * 1994-02-14 1995-03-07 Bel Electronics, Inc. Joint construction between military rocket motor and warhead and releasable by melting of fusible eutectic wedging ring for operating flexible locking fingers
US5507231A (en) * 1994-10-13 1996-04-16 Thiokol Corporation Solid fuel launch vehicle destruction system and method
US5792981A (en) 1996-10-28 1998-08-11 Thiokol Corporation Gun-launched rocket
FR2765958B1 (en) * 1997-07-11 1999-09-24 Tda Armements Sas MORTAR LOADING SYSTEM AND MORTAR EQUIPPED WITH SUCH A SYSTEM
US6338242B1 (en) 2000-07-26 2002-01-15 The United States Of America As Represented By The Secretary Of The Navy Vented MK 66 rocket motor tube with a thermoplastic warhead adapter
US6619029B2 (en) * 2001-11-01 2003-09-16 Alliant Techsystems Inc. Rocket motors with insensitive munitions systems
FR2873199B1 (en) * 2004-07-16 2006-09-22 Giat Ind Sa DEVICE FOR DECONFINING A HOUSING COMPRISING AT LEAST ONE PYROTECHNIC ELEMENT
FR2922638B1 (en) * 2007-10-23 2013-07-05 Tda Armements Sas ENERGY LOADING WITH CONTROLLED DECONFINEMENT AND AMMUNITION EQUIPPED WITH SUCH LOADING
FR2968392B1 (en) * 2010-12-03 2013-06-28 Tda Armements Sas DEVICE FOR CURING A MECHANICAL PROPELLER LINK FOR MORTAR MORTARING AND MUNITION COMPRISING SUCH A LINK
US10113846B2 (en) 2016-07-07 2018-10-30 General Dynamics Ordnance and Tactical Systems-Canada, Inc. Systems and methods for reducing munition sensitivity

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Also Published As

Publication number Publication date
DE69204803D1 (en) 1995-10-19
DE69204803T2 (en) 1996-02-22
FR2684439B1 (en) 1995-03-31
EP0545764A1 (en) 1993-06-09
FR2684439A1 (en) 1993-06-04
US5337672A (en) 1994-08-16

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