EP0546924A1 - Ejection piston with inflatable shock absorber - Google Patents

Ejection piston with inflatable shock absorber Download PDF

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Publication number
EP0546924A1
EP0546924A1 EP92403320A EP92403320A EP0546924A1 EP 0546924 A1 EP0546924 A1 EP 0546924A1 EP 92403320 A EP92403320 A EP 92403320A EP 92403320 A EP92403320 A EP 92403320A EP 0546924 A1 EP0546924 A1 EP 0546924A1
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EP
European Patent Office
Prior art keywords
piston
membrane
submunition
called
passage
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.)
Withdrawn
Application number
EP92403320A
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German (de)
French (fr)
Inventor
Gilles Doisneau
Jean-Pierre Frehaut
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thomson Brandt Armements SA
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Thomson Brandt Armements SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Thomson Brandt Armements SA filed Critical Thomson Brandt Armements SA
Publication of EP0546924A1 publication Critical patent/EP0546924A1/en
Withdrawn legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B12/00—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material
    • F42B12/02—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material characterised by the warhead or the intended effect
    • F42B12/36—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material characterised by the warhead or the intended effect for dispensing materials; for producing chemical or physical reaction; for signalling ; for transmitting information
    • F42B12/56—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material characterised by the warhead or the intended effect for dispensing materials; for producing chemical or physical reaction; for signalling ; for transmitting information for dispensing discrete solid bodies
    • F42B12/58—Cluster or cargo ammunition, i.e. projectiles containing one or more submissiles
    • F42B12/62—Cluster or cargo ammunition, i.e. projectiles containing one or more submissiles the submissiles being ejected parallel to the longitudinal axis of the projectile

Definitions

  • the invention lies in the field of containers for ejectable charges, in particular but not exclusively, in the field of cargo projectiles.
  • a cargo projectile has an outer envelope inside which are housed one or more submunitions constituting the payload.
  • the projectile is designed to be able to open and eject its submunitions at a given point in its trajectory.
  • the ejection, or unloading is controlled by a rocket which activates a pyrotechnic gas generator whose pressure is confined in a closed volume of the cargo vector, one of the faces of this volume being constituted by the payload so that the thrust exerted on the charge leads to its expulsion from the cargo projectile.
  • a piston to isolate the charge from pressurized gases.
  • This piston generally has a guiding and sealing role. It is particularly necessary if the face of the payload on which it rests has fragile parts, for example detector parts such as an optic, an antenna, which cannot be in direct contact with the powdered gas under pressure. .
  • the piston is then shaped to transmit the forces induced by the pressure on resistant supports of the payload.
  • this material should not come between the piston and the submunition until after the exit of the projectile, so that it protects the submunition well from the protruding parts of the piston, in particular the parts which were resting on the solid parts of the submunition.
  • This material should also occupy as small a volume as possible in storage.
  • the subject of the invention is a piston for ejecting a load from a container, the piston comprising a so-called external face facing a so-called high pressure chamber and a so-called internal face facing one of the charges to be ejected, characterized in that the piston has attached to its internal face one or more membrane (s) deformable (s) capable of receiving via at least one passage between the external and internal faces of the piston a fraction of the pressure developed in the high pressure chamber.
  • the membrane In order to reduce costs and space, it is advantageous to fix the membrane to the internal face of the piston, for example by gluing, along a surface surrounding the line of intersection of the passage and the internal face.
  • the membrane may or may not be elastic. It is however desirable for it to be shaped so that after inflation it comes to extend so as to form a gas blanket in front of the protruding parts of the piston.
  • the gas passage can consist of a simple nozzle forming a sonic nozzle so as to control the flow.
  • This solution is economical but has the drawback if the nozzle forming hole is too small in diameter, to be sensitive to tolerances.
  • several nozzles can be used in parallel to supply several membranes.
  • This material can be a porous material, for example a ceramic or a sintered metal.
  • the invention is applicable to any container for ejectable charges and more particularly to a cargo projectile. It is of particular interest in the case where the cargo projectile is a shell fired into a cannon and must support strong acceleration.
  • the membrane being very light does not induce a significant inertial load on the fragile part on which it rests.
  • Figure 1 is intended to show the use of the piston in the general configuration of a container having loads stored in line, the piston being intended to transmit the thrust of ejection to the loads.
  • the container is a projectile (1) comprising submunitions (20), three of which (21, 22 and 23) are shown in FIG. 1.
  • the projectile comprises, at the front a high pressure chamber (4), the high pressure chamber being powered by a gas generator (3) which in the case shown in Figure 1 is a pyrotechnic gas generator.
  • the piston (50) has an external face (51) facing the high pressure chamber (4) and an internal face (52) facing the first submunition (21). This piston is supported on solid parts (24) of the first submunition (21).
  • the solid part (24) of the submunition (21) is particularly simple since it is a peripheral ring to the submunition.
  • the piston therefore has a bell shape, the exterior of which faces the high pressure chamber (4) and the interior of which faces the submunition (21).
  • the piston comprises, for example glued on its inner face (52), a membrane (60). It also includes a passage (54) which allows the gas from the high pressure chamber (4) to press on the membrane (60).
  • the piston is shown in more detail in FIG. 2 and in FIG. 3.
  • the piston (50) is again seen with its external face (51) and its internal face (52), the membrane (60) is represented by a broken line, it is glued to a surface (53) which surrounds the passage (54) made through the piston to allow the gas from the high pressure chamber to have access to the interior of the piston and thus to come to press on the membrane (60).
  • Figure 3 in the deployed position.
  • the membrane (60) overflows and comes in masking, in particular of the projecting parts (55) which when the piston is inside the cargo ship, come to bear on the solid parts (24) of the first submunition.
  • the general configuration of the projectile and of the solid parts of the submunition are particularly simple since it is a projectile comprising only one line of ammunition, this line being located in axis xx 'of the projectile and the parts protruding being formed by cylinders surrounding each of the submunitions.
  • the invention is however applicable to containers comprising several load lines, each load having support points which may have a more complex structure.
  • the piston may have another shape and it may be advantageous to have several membranes in the part facing the load so that when the membranes are swollen, the set of membranes protects the rear face of the piston. and constitutes a shock-absorbing air mattress.
  • the passage (54) is in the case of the representation of Figures 1 to 3, a simple nozzle because it is a simple structure, the piston having only one wall. The function of this nozzle is to allow a slow passage of gases from the high pressure chamber into the low pressure chamber which is located on the other side of the piston.
  • the goal is that the pressure inside the low pressure chamber, between the membrane (60) and the internal face (52) of the piston (50), is sufficient at the end of ejection to inflate the membrane and thus constitute a clean air mattress to absorb shocks.
  • the membrane must therefore be slightly swollen.
  • the diameter of the nozzle (54) is calculated, in a manner known to a person skilled in the art, as a function of the pressure curve in the high pressure chamber and the time of ejection of the charges from the container.
  • the pressure curve as a function of time passes through a very large maximum and decreases very rapidly after a few milliseconds, the charges then being completely ejected.
  • the diameter of the nozzle is therefore very small and it may happen that it closes under the effect of combustion residue from the powder of the gas generator.
  • FIG. 4 another mode of passage has been shown in FIG. 4, in this case it is a passage constituted by a hole of larger diameter (59) allowing communication between the external face (51 ) and internal (52) of the piston, this hole being closed by a porous material (58) preferably a sintered metal.
  • FIG. 4 also shows the membrane (60), the latter optionally comprising foam parts (61) located at the places where the shocks are either the most probable or dangerous because they are located near particularly protruding parts. of the piston (50).
  • Figure 5 is intended to show two alternative embodiments of the piston.
  • the first of these variants relates to the shape of the passage 54.
  • This passage is carried out by two nozzles 54 (1) 54 (3) placed in series with one another.
  • the first 54 (1) is formed through a first wall 57 (1) of the piston
  • the second 54 (3) is formed through a second wall 57 (2) of the piston.
  • the two walls are separated by an intermediate chamber 54 (2).
  • This embodiment allows holes 54 (1), 54 (3) of larger diameter to be produced.
  • the hole configuration in series, intermediate chamber can be achieved by any other means and in particular by means of a part or a set of two parts which are fixed on a wall of the piston.
  • the second of these variants relates to the bearing face of the piston on the first load 21.
  • the solid bearing area 24 of the load 21 is a peripheral ring of the load.
  • the piston therefore comprises a zone in the form of a crown 55 which comes to bear on the strong part 24.
  • the zone 55 is connected to a zone 56 which comes into engagement on a corresponding projecting part 25 of the load 20 having the form of a ring circular.
  • FIGS. 1 to 5 are not limiting of the shape that can take the piston in particular the foam protectors (61) can be mounted on a piston having a passage formed by a nozzle (54) as shown in Figures 1 and 2. Likewise the sintered metal plug can be mounted on a piston whose membrane does not have a protective part (61).

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Toys (AREA)
  • Fluid-Damping Devices (AREA)

Abstract

Piston for ejecting a charge (20) from a container (1), the piston (50) comprising a so-called outer face (51) confronting a so-called high-pressure chamber (4) and a so-called inner face (52) confronting one of the charges to be ejected (21), characterised in that the piston (50) comprises, fastened to its inner face (52), one or more deformable diaphragms (60) capable of receiving, by means of at least one passage (54) between the outer (51) and inner (52) faces of the piston (50), a fraction of the pressure generated in the high-pressure chamber (4). <IMAGE>

Description

L'invention se situe dans le domaine des conteneurs pour charges éjectables, en particulier mais non exclusivement, dans le domaine des projectiles cargo.The invention lies in the field of containers for ejectable charges, in particular but not exclusively, in the field of cargo projectiles.

Elle concerne plus précisément les pistons d'éjection de charges ou sous munitions. On sait qu'un projectile cargo comporte une enveloppe extérieure à l'intérieur de laquelle sont logées une ou plusieurs sous-munitions constituant la charge utile. Le projectile est prévu pour pouvoir s'ouvrir et éjecter ses sous-munitions en un point donné de sa trajectoire.It relates more precisely to the charge ejection or submunition pistons. We know that a cargo projectile has an outer envelope inside which are housed one or more submunitions constituting the payload. The projectile is designed to be able to open and eject its submunitions at a given point in its trajectory.

Usuellement l'éjection, ou dépotage, est commandée par une fusée qui active un générateur pyrotechnique de gaz dont la pression est confinée dans un volume clos du vecteur cargo, une des faces de ce volume étant constituée par la charge utile de manière que la poussée exercée sur la charge entraîne son expulsion hors du projectile cargo. Il est classique d'intercaler une pièce dite piston pour isoler la charge des gaz sous pression. Ce piston a en général un rôle de guidage et d'étanchéïté. Il est particulièrement nécessaire si la face de la charge utile sur laquelle il s'appuie comporte des parties fragiles par exemple des parties de détecteur telle qu'une optique, une antenne, qui ne peuvent être en contact direct avec les gaz de poudre sous pression. Le piston est alors conformé pour transmettre les efforts induits par la pression sur des appuis résistants de la charge utile.Usually the ejection, or unloading, is controlled by a rocket which activates a pyrotechnic gas generator whose pressure is confined in a closed volume of the cargo vector, one of the faces of this volume being constituted by the payload so that the thrust exerted on the charge leads to its expulsion from the cargo projectile. It is conventional to insert a piece called a piston to isolate the charge from pressurized gases. This piston generally has a guiding and sealing role. It is particularly necessary if the face of the payload on which it rests has fragile parts, for example detector parts such as an optic, an antenna, which cannot be in direct contact with the powdered gas under pressure. . The piston is then shaped to transmit the forces induced by the pressure on resistant supports of the payload.

Le problème qui se pose est que le piston est usuellement éjecté avec la charge utile et doit s'en séparer ultérieurement. En effet la vitesse relative d'ejection qui atteint classiquement plusieurs dizaines de mètres par seconde et la géométrie interne du cargo font que l'arrêt du piston et sa non éjection seraient très délicats à réaliser.The problem is that the piston is usually ejected with the payload and must separate later. Indeed, the relative speed of ejection which conventionally reaches several tens of meters per second and the internal geometry of the cargo make the stopping of the piston and its non-ejection would be very difficult to achieve.

Tant que le piston est à l'intérieur du projectile, en phase d'éjection des sous-munitions, le piston appuie bien sur les parties solides de la sous-munition et seulement sur celles-ci. Par contre, dès que le piston quitte le projectile il est pris dans le vent relatif et soumis à des mouvements erratiques au cours desquels il risque de heurter une paroi, en général la face avant, de la sous-munition. Ce choc, même s'il s'agit d'un choc léger peut gravement endommager un élément de capteur qui serait placé sur cette face. Le dommage causé est aggravé si les pièces (sous-munition et piston) sont en mouvement de rotation rapide, par exemple dans le cas d'un cargo stabilisé par rotation,car on a alors de très forts frottements du piston sur la face avant dès qu'il y a excentrement des deux pièces. Ces frottement génèrent des moments de basculement qui se traduisent par un mouvement relatif d'oscillation conique des deux pièces. L'établissement de ce mouvement est beaucoup plus rapide que le mouvement de séparation des deux pièces et il en résulte un martèlement des faces en impact qui peut être très violent. Pour éviter cet endommagement il est prévu selon l'invention de munir la face du piston qui est en regard de la sous-munition d'un élément destiné à amortir un choc éventuel et à le rendre inoffensif par interposition entre la sous-munition et le piston d'un matériau mou par exemple un coussin de gaz ou un matériau mou par lui-même par exemple une mousse. Il convient cependant que ce matériau ne vienne s'interposer entre le piston et la sous-munition qu'après la sortie du projectile, de façon à ce qu'il protège bien la sous-munition des parties saillantes du piston, en particulier les parties qui étaient en appui sur les parties solides de la sous-munition. Il convient aussi que ce matériau occupe en stockage un volume aussi faible que possible.As long as the piston is inside the projectile, in the phase of ejection of the submunitions, the piston presses well on the solid parts of the submunition and only on these. On the other hand, as soon as the piston leaves the projectile it is caught in the relative wind and subjected to erratic movements during which it risks striking a wall, generally the front face, of the submunition. This shock, even if it is a light shock, can seriously damage a sensor element which is placed on this face. The damage caused is aggravated if the parts (submunition and piston) are in rapid rotation movement, for example in the case of a cargo stabilized by rotation, because there is then very strong friction of the piston on the front face from that there is eccentricity of the two parts. These friction generate tilting moments which result in a relative conical oscillation movement of the two parts. The establishment of this movement is much faster than the movement of separation of the two parts and this results in a hammering of the impact faces which can be very violent. To avoid this damage, it is provided according to the invention to provide the face of the piston which is opposite the submunition with an element intended to absorb a possible shock and to make it harmless by interposition between the submunition and the piston of a soft material for example a gas cushion or a soft material by itself for example a foam. However, this material should not come between the piston and the submunition until after the exit of the projectile, so that it protects the submunition well from the protruding parts of the piston, in particular the parts which were resting on the solid parts of the submunition. This material should also occupy as small a volume as possible in storage.

A cette fin l'invention a pour objet un piston d'éjection d'une charge d'un conteneur, le piston comportant une face dite externe en regard d'une chambre dite haute pression et une face dite interne en regard d'une des charges à éjecter, caractérisé en ce que le piston comporte fixée(s) à sa face interne une ou plusieurs membrane(s) déformable(s) capable de recevoir par l'intermédiaire d'au moins un passage entre les faces externes et internes du piston une fraction de la pression développée dans la chambre haute pression.To this end, the subject of the invention is a piston for ejecting a load from a container, the piston comprising a so-called external face facing a so-called high pressure chamber and a so-called internal face facing one of the charges to be ejected, characterized in that the piston has attached to its internal face one or more membrane (s) deformable (s) capable of receiving via at least one passage between the external and internal faces of the piston a fraction of the pressure developed in the high pressure chamber.

Au moment de l'éjection un générateur de gaz est amorcé et la pression monte dans la chambre haute pression, à une valeur de l'ordre de plusieurs centaines de bars. Le passage entre la face interne et la face externe du piston doit être tel que la pression dans le compartiment limité par la face interne du piston et la membrane s'élève à une pression supérieure à la pression dynamique de l'air à la vitesse de dépotage, de l'ordre de 1,5 à 2 bars. De la sorte lorsque le piston quitte le projectile, la membrane se gonfle sous l'effet de cette pression et constitue un "pare-choc" qui vient amortir un choc éventuel entre la sous-munition et le piston.At the time of ejection a gas generator is started and the pressure rises in the high pressure chamber, to a value of the order of several hundred bars. The passage between the internal face and the external face of the piston must be such that the pressure in the compartment limited by the internal face of the piston and the membrane rises to a pressure higher than the dynamic pressure of the air at the speed of unloading, of the order of 1.5 to 2 bars. In this way when the piston leaves the projectile, the membrane swells under the effect of this pressure and constitutes a "bumper" which absorbs any impact between the submunition and the piston.

Afin de diminuer les coûts et l'encombrement il est avantageux de fixer la membrane à la face interne du piston, par exemple par collage, le long d'une surface entourant la ligne d'intersection du passage et de la face interne.In order to reduce costs and space, it is advantageous to fix the membrane to the internal face of the piston, for example by gluing, along a surface surrounding the line of intersection of the passage and the internal face.

Pour adoucir les chocs encore davantage et pour mieux entourer de manière molle les parties saillantes du piston on peut disposer en des points de la membrane qui après gonflage sont proches des parties saillantes des matières molles tels que de la mousse. La membrane peut être élastique ou non. Il est cependant souhaitable qu'elle soit conformée de telle sorte qu'après gonflage elle vienne s'étendre de façon à former un matelas de gaz devant les parties saillantes du piston.To soften the shocks even more and to better softly surround the protruding parts of the piston, it is possible to arrange at points on the membrane which, after inflation, are close to the protruding parts of soft materials such as foam. The membrane may or may not be elastic. It is however desirable for it to be shaped so that after inflation it comes to extend so as to form a gas blanket in front of the protruding parts of the piston.

Le passage des gaz peut être constitué d'un simple ajutage formant tuyère sonique de manière à controler le débit. Cette solution est économique mais présente l'inconvénient si le trou formant ajutage est de diamètre trop faible, d'être sensible aux tolérances. Pour obtenir plus aisément un fort différentiel de pression et réduire l'importance des tolérances de diamètre, on peut prévoir plusieurs ajutages, par exemple deux, disposés en série et séparés par une chambre à pression intermédiaire de façon que la pression ne monte que faiblement et relativement plus lentement dans le compartiment dont la membrane constitue une des faces. Par ailleurs dans le cas d'un piston de forme complexe plusieurs ajutages peuvent être utilisés en parallèle pour alimenter plusieurs membranes. Il peut être judicieux également de réaliser un passage de plus fort diamètre au moyen d'un trou traversant, le trou étant obturé par une matière perméable au gaz lorsqu'il existe un fort différentiel de pression. Cette matière peut être une matière poreuse par exemple une céramique ou un métal fritté.The gas passage can consist of a simple nozzle forming a sonic nozzle so as to control the flow. This solution is economical but has the drawback if the nozzle forming hole is too small in diameter, to be sensitive to tolerances. To more easily obtain a high pressure differential and reduce the importance of diameter tolerances, it is possible to provide several nozzles, for example two, arranged in series and separated by a pressure chamber intermediate so that the pressure rises only slightly and relatively more slowly in the compartment of which the membrane constitutes one of the faces. Furthermore, in the case of a piston of complex shape, several nozzles can be used in parallel to supply several membranes. It may also be advisable to make a passage of larger diameter by means of a through hole, the hole being closed by a material permeable to gas when there is a high pressure differential. This material can be a porous material, for example a ceramic or a sintered metal.

L'invention est applicable à tout conteneur pour charges éjectables et plus particulièrement à un projectile cargo. Elle présente un intérêt particulier dans le cas ou le projectile cargo est un obus tiré dans un canon et doit supporter une forte accélération. La membrane étant très légère n'induit pas de charge inertielle importante sur la partie fragile sur laquelle elle s'appuie.The invention is applicable to any container for ejectable charges and more particularly to a cargo projectile. It is of particular interest in the case where the cargo projectile is a shell fired into a cannon and must support strong acceleration. The membrane being very light does not induce a significant inertial load on the fragile part on which it rests.

Une description détaillée d'un mode de réalisation de l'invention appliqué à un projectile cargo sera maintenant effectuée en regard des dessins annexés dans lesquels :

  • la figure 1 représente la partie avant d'un projectile comprenant le piston selon l'invention.
  • la figure 2 est une coupe du piston selon l'invention.
  • la figure 3 est une coupe d'un piston selon l'invention montrant la membrane déployée.
  • la figure 4 est une coupe du piston selon l'invention montrant l'utilisation d'un bouchon en matière poreuse et de mousse d'amortissement supplémentaire.
  • la figure 5 est une représentation d'un piston avec chambre intermédiaire et dispositif d'emboîtement.
A detailed description of an embodiment of the invention applied to a cargo projectile will now be made with reference to the appended drawings in which:
  • Figure 1 shows the front part of a projectile comprising the piston according to the invention.
  • Figure 2 is a section of the piston according to the invention.
  • Figure 3 is a section of a piston according to the invention showing the deployed membrane.
  • Figure 4 is a section of the piston according to the invention showing the use of a plug of porous material and additional damping foam.
  • Figure 5 is a representation of a piston with intermediate chamber and interlocking device.

La figure 1 est destinée à montrer l'emploi du piston dans la configuration générale d'un conteneur comportant des charges rangées en ligne, le piston étant destiné à transmettre la poussée d'éjection aux charges. Dans le cas particulier représenté sur la figure 1, le conteneur est un projectile (1) comprenant des sous-munitions ( 20) dont trois ( 21, 22 et 23) sont représentées sur la figure 1. Le projectile comprend, à l'avant une chambre haute pression (4), la chambre haute pression étant alimentable par un générateur de gaz (3) qui dans le cas représenté sur la figure 1 est un générateur de gaz pyrotechnique. Le piston (50) comporte une face externe (51) tournée vers la chambre haute pression (4) et une face interne (52) tournée vers la première sous-munition (21). Ce piston est en appui sur des parties solides (24) de la première sous-munition (21).Figure 1 is intended to show the use of the piston in the general configuration of a container having loads stored in line, the piston being intended to transmit the thrust of ejection to the loads. In the particular case shown in Figure 1, the container is a projectile (1) comprising submunitions (20), three of which (21, 22 and 23) are shown in FIG. 1. The projectile comprises, at the front a high pressure chamber (4), the high pressure chamber being powered by a gas generator (3) which in the case shown in Figure 1 is a pyrotechnic gas generator. The piston (50) has an external face (51) facing the high pressure chamber (4) and an internal face (52) facing the first submunition (21). This piston is supported on solid parts (24) of the first submunition (21).

Dans le cas représenté figure 1, la partie solide (24) de la sous-munition (21) est particulièrement simple puisqu'il s'agit d'une couronne périphérique à la sous-munition. Le piston à donc une forme de cloche dont l'extérieur est tourné vers la chambre haute pression (4) et l'intérieur tourné vers la sous-munition (21). Le piston comprend, par exemple collée sur sa face intérieure (52), une membrane (60). Il comprend également un passage (54) qui permet au gaz de la chambre haute pression (4) de venir presser sur la membrane (60). Le piston est représenté plus en détail figure 2 et figure 3.In the case shown in Figure 1, the solid part (24) of the submunition (21) is particularly simple since it is a peripheral ring to the submunition. The piston therefore has a bell shape, the exterior of which faces the high pressure chamber (4) and the interior of which faces the submunition (21). The piston comprises, for example glued on its inner face (52), a membrane (60). It also includes a passage (54) which allows the gas from the high pressure chamber (4) to press on the membrane (60). The piston is shown in more detail in FIG. 2 and in FIG. 3.

Sur la figure 2, on voit de nouveau le piston (50) avec sa face externe (51) et sa face interne (52), la membrane (60) est représentée par une ligne brisée, elle est collée sur une surface (53) qui entoure le passage (54) pratiqué à travers le piston pour permettre au gaz de la chambre haute pression d'avoir accès à l'intérieur du piston et de venir ainsi faire pression sur la membrane (60). Celle-ci est représentée sur la figure 3 en position déployée. On voit sur cette figure que la membrane (60) déborde et vient en masquage, en particulier des parties saillantes (55) qui lorsque le piston est à l'intérieur du cargo, viennent en appui sur les parties solides (24) de la première sous-munition. Dans le cas représenté figure 1 à 3, la configuration générale du projectile et des parties solides de la sous munition sont particulièrement simples puisqu'il s'agit d'un projectile ne comportant qu'une seule ligne de munitions, cette ligne étant située dans l'axe x x' du projectile et les parties saillantes étant constituées par des cylindres entourant chacune des sous-munitions.In FIG. 2, the piston (50) is again seen with its external face (51) and its internal face (52), the membrane (60) is represented by a broken line, it is glued to a surface (53) which surrounds the passage (54) made through the piston to allow the gas from the high pressure chamber to have access to the interior of the piston and thus to come to press on the membrane (60). This is shown in Figure 3 in the deployed position. We see in this figure that the membrane (60) overflows and comes in masking, in particular of the projecting parts (55) which when the piston is inside the cargo ship, come to bear on the solid parts (24) of the first submunition. In the case shown in FIGS. 1 to 3, the general configuration of the projectile and of the solid parts of the submunition are particularly simple since it is a projectile comprising only one line of ammunition, this line being located in axis xx 'of the projectile and the parts protruding being formed by cylinders surrounding each of the submunitions.

L'invention est cependant applicable à des conteneurs comprenant plusieurs lignes de charge, chaque charge ayant des points d'appui pouvant avoir une structure plus complexe. Dans ce cas, le piston peut avoir une autre forme et il peut être avantageux de disposer plusieurs membranes dans la partie faisant face à la charge de façon à ce que lorsque les membranes sont gonflées, l'ensemble des membranes protège la face arrière du piston et lui constitue un matelas d'air amortisseur de chocs. Le passage (54) est dans le cas de la représentation des figures 1 à 3, un simple ajutage car il s'agit d'une structure simple, le piston ne comportant qu'une paroi. La fonction de cette ajutage est de permettre un passage lent des gaz de la chambre haute pression dans la chambre basse pression qui est située de l'autre côté du piston. Le but à atteindre est que la pression à l'intérieur de la chambre basse pression, comprise entre la membrane (60) et la face interne (52) du piston (50), soit suffisante en fin d'éjection pour gonfler la membrane et constituer ainsi un matelas d'air propre à amortir les chocs. La membrane doit donc être faiblement gonflée. Le diamètre de l'ajutage (54) est calculé, de façon connue de l'homme du métier en fonction de la courbe de pression dans la chambre haute pression et du temps d'éjection des charges du conteneur.The invention is however applicable to containers comprising several load lines, each load having support points which may have a more complex structure. In this case, the piston may have another shape and it may be advantageous to have several membranes in the part facing the load so that when the membranes are swollen, the set of membranes protects the rear face of the piston. and constitutes a shock-absorbing air mattress. The passage (54) is in the case of the representation of Figures 1 to 3, a simple nozzle because it is a simple structure, the piston having only one wall. The function of this nozzle is to allow a slow passage of gases from the high pressure chamber into the low pressure chamber which is located on the other side of the piston. The goal is that the pressure inside the low pressure chamber, between the membrane (60) and the internal face (52) of the piston (50), is sufficient at the end of ejection to inflate the membrane and thus constitute a clean air mattress to absorb shocks. The membrane must therefore be slightly swollen. The diameter of the nozzle (54) is calculated, in a manner known to a person skilled in the art, as a function of the pressure curve in the high pressure chamber and the time of ejection of the charges from the container.

Dans le cas de la réalisation, la courbe de pression en fonction du temps passe par un maximum très important et décroît très rapidement au bout de quelques millisecondes les charges étant alors complètement éjectées. Le diamètre de l'ajutage est donc très faible et il peut arriver qu'il s'obture sous l'effet de résidu de combustion de la poudre du générateur de gaz.In the case of production, the pressure curve as a function of time passes through a very large maximum and decreases very rapidly after a few milliseconds, the charges then being completely ejected. The diameter of the nozzle is therefore very small and it may happen that it closes under the effect of combustion residue from the powder of the gas generator.

Pour parer à cette possibilité de disfonctionnement, un autre mode de passage a été représenté figure 4, il s'agit dans ce cas d'un passage constitué par un trou de diamètre plus large (59) permettant la communication entre la face externe (51) et interne (52) du piston, ce trou étant obturé par une matière poreuse (58) de préférence un métal fritté.To counter this possibility of malfunction, another mode of passage has been shown in FIG. 4, in this case it is a passage constituted by a hole of larger diameter (59) allowing communication between the external face (51 ) and internal (52) of the piston, this hole being closed by a porous material (58) preferably a sintered metal.

Il a été représenté également figure 4, la membrane (60), cette dernière comportant facultativement des parties en mousse (61) situées aux endroits où les chocs sont soit les plus probables soit dangereux du fait qu'ils se situent près de parties particulièrement saillantes du piston (50).FIG. 4 also shows the membrane (60), the latter optionally comprising foam parts (61) located at the places where the shocks are either the most probable or dangerous because they are located near particularly protruding parts. of the piston (50).

La figure 5 est destinée à faire apparaître deux variantes de réalisation du piston.Figure 5 is intended to show two alternative embodiments of the piston.

La première de ces variantes est relative à la forme du passage 54.The first of these variants relates to the shape of the passage 54.

Ce passage est réalisée par deux ajutages 54(1) 54(3) placés en série l'un par rapport à l'autre. Le premier 54(1) est pratiqué à travers une première paroi 57(1) du piston, le second 54(3) est pratiqué à travers une seconde paroi 57(2) du piston. Les deux parois sont séparées par une chambre intermédiaire 54(2). Cette forme de réalisation permet de réaliser des trous 54(1), 54(3) de plus grand diamètre.This passage is carried out by two nozzles 54 (1) 54 (3) placed in series with one another. The first 54 (1) is formed through a first wall 57 (1) of the piston, the second 54 (3) is formed through a second wall 57 (2) of the piston. The two walls are separated by an intermediate chamber 54 (2). This embodiment allows holes 54 (1), 54 (3) of larger diameter to be produced.

La configuration trous en série, chambre intermédiaire peut être réalisée par tout autre moyens et notamment par l'intermédiaire d'une pièce ou d'un ensemble de deux pièces venant se fixer sur une paroi du piston.The hole configuration in series, intermediate chamber can be achieved by any other means and in particular by means of a part or a set of two parts which are fixed on a wall of the piston.

La seconde de ces variantes est relatives à la face d'appui du piston sur la première charge 21. Dans le cas représenté figure 5, la zone d'appui solide 24 de la charge 21 est une couronne périphérique de la charge. Le piston comporte donc une zone en forme de couronne 55 venant en appui sur la partie forte 24. La zone 55 est raccordée à une zone 56 qui vient en emboïtement sur une partie correspondante saillante 25 de la charge 20 ayant la forme d'une bague circulaire .The second of these variants relates to the bearing face of the piston on the first load 21. In the case shown in FIG. 5, the solid bearing area 24 of the load 21 is a peripheral ring of the load. The piston therefore comprises a zone in the form of a crown 55 which comes to bear on the strong part 24. The zone 55 is connected to a zone 56 which comes into engagement on a corresponding projecting part 25 of the load 20 having the form of a ring circular.

L'emboîtement du piston sur la périphérie de la face , la charge ou comme représenté figure 5 sur un prolongement 26 de celle-ci crée un guidage axial du piston facilitant sa séparation axiale après la fin de l'éjection sous l'influence de la poussée développée par la membrane sous pression.The fitting of the piston on the periphery of the face, the load or as shown in FIG. 5 on an extension 26 of the latter creates an axial guidance of the piston facilitating its axial separation after the end of ejection under the influence of the thrust developed by the membrane under pressure.

Les formes représentées sur les figures 1 à 5 ne sont pas limitatives de la forme que peut prendre le piston en particulier les protecteurs en mousse (61) peuvent être montés sur un piston comportant un passage formé par un ajutage (54) comme représenté figures 1 et 2. De même le bouchon en métal fritté peut être monté sur un piston dont la membrane ne comporte pas de partie protectrice (61).The shapes shown in Figures 1 to 5 are not limiting of the shape that can take the piston in particular the foam protectors (61) can be mounted on a piston having a passage formed by a nozzle (54) as shown in Figures 1 and 2. Likewise the sintered metal plug can be mounted on a piston whose membrane does not have a protective part (61).

Le fonctionnement est le suivant :The operation is as follows:

A la mise en pression de la chambre haute pression, les gaz de la chambre haute pression passent lentement dans la partie interne du piston et viennent gonfler la membrane (60). Celle-ci ne peut toutefois se déployer que lorsque le piston (50) sort du projectile car tant qu'il est à l'intérieur du projectile, la faible pression exercée sur la membrane est contrebalancée par la face avant de la sous-munition. Par contre, dès que le piston sort du projectile, la membrane n'est plus soumise qu'à la contre pression extérieure et à sa pression interne et peut alors, se déployer et jouer son rôle de matelas protecteur contre les chocs.When the high pressure chamber is pressurized, the gases from the high pressure chamber pass slowly through the internal part of the piston and inflate the membrane (60). However, this can only deploy when the piston (50) leaves the projectile because as long as it is inside the projectile, the low pressure exerted on the membrane is counterbalanced by the front face of the submunition. On the other hand, as soon as the piston leaves the projectile, the membrane is no longer subjected only to the external counter pressure and to its internal pressure and can then deploy and play its role of protective mattress against shocks.

Claims (13)

Piston d'éjection d'une charge (20) d'un conteneur (1), le piston (50) comportant une face dite externe (51) en regard d'une chambre (4) dite haute pression et une face dite interne (52) en regard d'une des charges à éjecter (21), caractérisé en ce que le piston (50) comporte fixée(s) à sa face interne (52) une ou plusieurs membrane(s) (60) déformable(s) capable de recevoir par l'intermédiaire d'au moins un passage (54) entre les faces externes (51) et internes (52) du piston (50) une fraction de la pression développée dans la chambre haute pression (4).Piston for ejecting a load (20) from a container (1), the piston (50) comprising a so-called external face (51) facing a chamber (4) called high pressure and a so-called internal face ( 52) opposite one of the charges to be ejected (21), characterized in that the piston (50) has fixed (s) to its internal face (52) one or more deformable membrane (s) (60) capable of receiving via at least one passage (54) between the external (51) and internal (52) faces of the piston (50) a fraction of the pressure developed in the high pressure chamber (4). Piston selon la revendication 1, caractérisé en ce que la membrane (60) est fixée à la face interne (52) selon une surface (53) entourant la ligne formée par l'intersection du passage (54) et de la face interne (52) du piston (50).Piston according to claim 1, characterized in that the membrane (60) is fixed to the internal face (52) according to a surface (53) surrounding the line formed by the intersection of the passage (54) and the internal face (52 ) of the piston (50). Piston (50) selon la revendication 2, caractérisé en ce que la membrane (60) est fixée à sa face interne (52) par collage.Piston (50) according to claim 2, characterized in that the membrane (60) is fixed to its internal face (52) by gluing. Piston (50) selon la revendication 2, caractérisé en ce que la membrane (60) comporte une matière compressible (61) sur une partie au moins de sa surface.Piston (50) according to claim 2, characterized in that the membrane (60) comprises a compressible material (61) on at least part of its surface. Piston (50) selon la revendication 2, caractérisé en ce que la membrane (60) est élastique.Piston (50) according to claim 2, characterized in that the membrane (60) is elastic. Piston (50) selon la revendication 2, caractérisé en ce que la membrane (60) est plissée.Piston (50) according to claim 2, characterized in that the membrane (60) is pleated. Piston (50) selon la revendication 2, caractérisé en ce que le passage (54) est constitué par au moins un ajutage de faible diamètre.Piston (50) according to claim 2, characterized in that the passage (54) consists of at least one nozzle of small diameter. Piston (50) selon la revendication 2, caractérisé en ce que le passage (54) est constitué par au moins un trou traversant (59) obturé par une matière poreuse (58).Piston (50) according to claim 2, characterized in that the passage (54) consists of at least one through hole (59) closed by a porous material (58). Piston (50) selon la revendication 8, caractérisé en ce que la matière poreuse (58) est un métal fritté.Piston (50) according to claim 8, characterized in that the porous material (58) is a sintered metal. Piston selon la revendication 2, caractérisé en ce que le passage (54) est constitué de deux ajutages disposées en série (54(1), 54(3)) séparés par une chambre à pression intermédiaire (54(2).Piston according to claim 2, characterized in that the passage (54) consists of two nozzles arranged in series (54 (1), 54 (3)) separated by an intermediate pressure chamber (54 (2). Piston selon la revendication 2, caractérisé en ce qu'il comporte une zone d'appui (55) conformée pour correspondre à des parties solides (24) d'une charge (20) à éjecter.Piston according to claim 2, characterized in that it comprises a support zone (55) shaped to correspond to solid parts (24) of a charge (20) to be ejected. Piston selon la revendication 11, caractérisé en ce qu'il comporte une zone (56) destinée à s'emboiter sur une partie correspondante (25) d'une charge (20) à éjecter.Piston according to claim 11, characterized in that it comprises a zone (56) intended to fit onto a corresponding part (25) of a charge (20) to be ejected. Projectile cargo (1) du type transportant une ou plusieurs sous-munitions (20) rangées dans le cargo sous forme d'au moins une ligne, les lignes de sous-munitions étant éjectables au moyen d'une pression exercée par des gaz, produits par un générateur (3) de gaz dans une chambre dite haute pression sur une première sous-munition (21) de la ligne, cette poussée étant transmise à cette sous-munition par une pièce intermédiaire (50) dite piston prenant appui sur des parties solides (24) de la première sous-munition (21), le piston ayant deux faces, une face 51 dite externe tournée vers la chambre haute pression (4) et une face (52) dite interne tournée vers la sous munition, projectile caractérisé en ce que le piston est conforme à l'une des revendications 1 à 12.Cargo projectile (1) of the type transporting one or more submunitions (20) stored in the freighter in the form of at least one line, the submunition lines being ejected by means of a pressure exerted by gases, products by a gas generator (3) in a so-called high pressure chamber on a first submunition (21) of the line, this thrust being transmitted to this submunition by an intermediate piece (50) called piston bearing on parts solids (24) of the first submunition (21), the piston having two faces, a so-called external face 51 facing the high pressure chamber (4) and a so-called internal face (52) facing the submunition, characterized projectile in that the piston conforms to one of claims 1 to 12.
EP92403320A 1991-12-13 1992-12-08 Ejection piston with inflatable shock absorber Withdrawn EP0546924A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9115519A FR2685073B1 (en) 1991-12-13 1991-12-13 EJECTION PISTON WITH INFLATABLE SHOCK ABSORBER.
FR9115519 1991-12-13

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EP0546924A1 true EP0546924A1 (en) 1993-06-16

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EP92403320A Withdrawn EP0546924A1 (en) 1991-12-13 1992-12-08 Ejection piston with inflatable shock absorber

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EP (1) EP0546924A1 (en)
FR (1) FR2685073B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104132585A (en) * 2014-07-02 2014-11-05 北京航天发射技术研究所 Flexible base with protecting layer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2738031A1 (en) * 1976-08-23 1978-03-02 Foerenade Fabriksverken DEVICE FOR EXHAUSTING AND SEPARATING BODIES FROM OR FROM ONE STOREY
GB2222668A (en) * 1988-09-07 1990-03-14 Secr Defence Munition release apparatus
FR2650066A1 (en) * 1989-07-24 1991-01-25 Rheinmetall Gmbh BEARING PROJECTILE

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2738031A1 (en) * 1976-08-23 1978-03-02 Foerenade Fabriksverken DEVICE FOR EXHAUSTING AND SEPARATING BODIES FROM OR FROM ONE STOREY
GB2222668A (en) * 1988-09-07 1990-03-14 Secr Defence Munition release apparatus
FR2650066A1 (en) * 1989-07-24 1991-01-25 Rheinmetall Gmbh BEARING PROJECTILE

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104132585A (en) * 2014-07-02 2014-11-05 北京航天发射技术研究所 Flexible base with protecting layer

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FR2685073B1 (en) 1994-02-04
FR2685073A1 (en) 1993-06-18

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