EP0091860A1 - Armour-piercing hollow charge - Google Patents

Armour-piercing hollow charge Download PDF

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Publication number
EP0091860A1
EP0091860A1 EP83400675A EP83400675A EP0091860A1 EP 0091860 A1 EP0091860 A1 EP 0091860A1 EP 83400675 A EP83400675 A EP 83400675A EP 83400675 A EP83400675 A EP 83400675A EP 0091860 A1 EP0091860 A1 EP 0091860A1
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Prior art keywords
charge
cavity
hollow
hollow charge
priming
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EP83400675A
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German (de)
French (fr)
Inventor
Gérard Pfeffer
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Thomson-Brandt SA
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Thomson-Brandt SA
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B1/00—Explosive charges characterised by form or shape but not dependent on shape of container
    • F42B1/02—Shaped or hollow charges
    • F42B1/028—Shaped or hollow charges characterised by the form of the liner

Definitions

  • the present invention relates to shaped charges; it relates more particularly to a perforating hollow charge intended for the drilling of holes in various bodies which are in monolithic or composite form.
  • the perforating hollow charges essentially comprise an explosive charge of revolution in which an open cavity having a metallic coating has been arranged, and an initiating device also having a symmetry of revolution.
  • the detonation wave of the shaped charge is triggered by the initiating device, which comprises a priming charge to which a primer is coupled, the firing of which is dependent on a control signal.
  • the characteristics of the initiating charge determine the profile of the detonation wave in the explosive charge as well as its isochronism.
  • the metallic coating of the cavity is set in motion and projects on the axis of symmetry of the hollow charge.
  • the result is a metallic projectile composed, on the one hand, of a metal jet animated at the head with a considerable speed which can reach 10 000 ms -1 , and on the other hand, of a metallic core animated with a speed more moderate, of the order of a few hundred meters / second.
  • These two components resulting from the implosion of the metallic coating of the cavity, both translate on the axis of symmetry of the hollow charge.
  • the passage of the perforating jet in a massive body leaves a crater of great depth and a relatively small diameter, while the metal core whose significant mass is a disturbing element which tends to block the hole left by the passage of the metal spray.
  • shaped charges are widely known, especially in the military art where they are used for perforate the protective armor of objectives, in particular combat vehicles, but they also find applications in the civil field for the perforation of casings of oil drilling, as well as the cement placed, if necessary behind the casing, and geological materials located behind the cement.
  • hollow charges have already been proposed and produced having a bimetallic coating, or according to a variant, a coating consisting of sintered metal powders.
  • the part of the coating which generates the metal core consists of a metal which is consumed in the air.
  • the metal core is pulverized and disintegrates after its formation.
  • a hollow charge intended for drilling a clear hole in a solid monolithic or composite body comprises an explosive charge of revolution in which an open cavity is formed having a metallic coating, and a priming charge, to produce a metallic projectile composed of a piercing jet and a core; in order to impart a substantially zero speed to the metal core, or preferably opposite to the direction of movement of the perforating jet, the radius of curvature of the profile of the cavity gradually increases as a function of the distance from the top to the base of the cavity .
  • the thickness of the metal coating of the cavity gradually increases as a function of the distance from the top to the base of the cavity.
  • the priming charge comprises a shaping device in order to initiate an annular detonation wave, such that the pressure forces applied to the external face of the metallic coating are perpendicular to this surface; in this shaper, a metallic cylindrical element is disposed axially, the function of this cylindrical element being to deflect the initiating wave radially without the power of the detonation wave being in any way diminished.
  • a central channel 9 intended to provide a free passage for the metal jet projected by the hollow charge, axially passes through the gas generator of the impeller 1 and the compartment 5 of the electronic circuits and opens out at the rear of the components. optics of the guide head, while the opposite end of this central channel opens, flaring on the base of the hollow charge cavity. It is important to note that the axial dimension x of the part flaring of the central channel must be minimized, which implies that the metal jet must converge quickly as soon as it forms.
  • the profile of the open cavity 11 is one of the parameters of construction of the hollow charge which governs the formation of a metallic core animated with a substantially zero speed, or preferentially negative, that is to say in a direction opposite to that of the piercing jet.
  • the radius of curvature Rc of the cavity must gradually increase from the top of the cavity to its base.
  • This law of variation of the radius of curvature of the cavity gives it a substantially hyperbolic shape profile, a typical shape of which is the "TULIP" shape, that is to say that the relationship between the radial distance Y and the axial distance x of the cavity is of the form: with O ⁇ x (xp and xp is the depth of the cavity.
  • the magnitudes of the coefficients AB and C depend on the physical dimensions of the shaped charge, in particular its caliber ⁇ p , the paths of the detonation wave in the main charge, but also on the nature of the explosive material used.
  • the depth xp of the cavity is then substantially greater than its opening ⁇ r , while the diameter ⁇ c of the explosive charge is greater than the opening ⁇ r of the cavity, so as to have a certain thickness of explosive, of the order of a few mm, around the base of the cavity.
  • the perforation performance of the hollow charge can be further improved, if together, the thickness e of the metal coating gradually increases from the top to the base of the cavity according to a relation of the form: with eo of the order of 0.06 O and e (Xp) substantially equal to 0.025 ⁇ c C.
  • the clearance distance x c in front of the opening of the cavity is relatively small, of the order of 0.06 ⁇ c , which significantly reduces the longitudinal dimensions of the hollow charge and, consequently, that of the military charge C.
  • the other parameters of the hollow charge which are more particularly associated with the device for initiating the detonation wave of the explosive charge must be taken into account since their influence on the profile and the isochronism of the detonation wave is significant. , and in particular, if we consider the annular initiation of the detonation wave.
  • the shaped charge which has just been described in detail has a configuration which is simple enough to optimize the values of the parameters and achieve the necessary perforation performance.
  • the usual precautions in this area must be observed: homogeneity and physical properties of the building materials, and perfect symmetry of revolution of the components of the hollow charge.
  • the security, arming and firing means, for example of the inertial type, which are known per se and have no influence on the invention are therefore not described here.
  • the respective weights of the main explosive and of the metallic coating are approximately 800g and 200g.
  • the main load and the auxiliary load can be constituted by an octagon composite;
  • the metallic coating of the cavity can be made of a metal such as copper;
  • the conformator is constructed of a plastic material or else of a vegetable material, such as wood;
  • the metallic cylindrical element, included in the shaper is made of a dense metallic material and preferably of steel.
  • the construction of the shaped charge may be simplified, in particular, the thickness of the metal lining of the cavity can be kept constant; the conformator included in the priming charge can be eliminated, or at least simplified, and the contact sections of the two charges can have a diameter equal to that of the shaped charge.
  • a hollow charge finds its application in the military art, but also in oil drilling and the drilling of holes of great depth in the coal layers.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)

Abstract

This hollow charge intended for piercing "clear" holes of great depth has rotational symmetry about an axis X and comprises an explosive charge (10) in which is made an open cavity (11) having a metal covering (12), and a priming device consisting of a priming charge (16) and ignition means (17); the profile of the cavity (11) is shaped so as to impart to the core and to the metal jet occurring as a result of the implosion of the metal covering translational speeds which are different and oppositely directed. The thickness (e) of the metal covering (12) increases progressively from the top of the cavity to the base, and the priming charge (16) comprises a shaper (14) including a cylindrical metal element (20) to ensure an annular ignition of the detonation wave. This hollow charge is used in the military and civil sectors.

Description

La présente invention se rapporte aux charges creuses ; elle concerne plus particulièrement une charge creuse perforante destinée au percement de trous dans des corps divers se présentant sous forme monolithique ou composite.The present invention relates to shaped charges; it relates more particularly to a perforating hollow charge intended for the drilling of holes in various bodies which are in monolithic or composite form.

On sait que les charges creuses perforantes comprennent essentiellement, un chargement explosif de révolution dans lequel on a aménagé une cavité ouverte ayant un revêtement métallique, et un dispositif d'amorçage ayant également une symétrie de révolution.It is known that the perforating hollow charges essentially comprise an explosive charge of revolution in which an open cavity having a metallic coating has been arranged, and an initiating device also having a symmetry of revolution.

L'onde de détonation de la charge creuse est déclenchée par le dispositif d'amorçage, qui comprend un chargement d'amorçage auquel est couplée une amorce, dont la mise à feu est dépendante d'un signal de commande. Les caractéristiques de la charge d'amorçage déterminent le profil de l'onde de détonation dans le chargement explosif ainsi que son isochronisme. Sous l'action des produits de détonation situés immédiatement derrière l'onde de détonation, le revêtement métallique de la cavité est mis en mouvement et se projète sur l'axe de symétrie de la charge creuse. Il en résulte un projectile métallique composé, d'une part, d'un jet de métal animé en tête d'une vitesse considérable pouvant atteindre 10 000ms-1, et d'autre part, d'un noyau métallique animé d'une vitesse plus modérée, de l'ordre de quelques centaines de mètres/seconde. Ces deux composantes, résultant de l'implosion du revêtement métallique de la cavité, se translatent toutes les deux sur l'axe de symétrie de la charge creuse. Le passage du jet perforant dans un corps massif laisse un cratère de grande profondeur et d'un diamètre relativement faible, tandis que le noyau métallique dont la masse relative est importante, est un élément perturbateur qui tend à obturer le trou laissé par le passage du jet de métal.The detonation wave of the shaped charge is triggered by the initiating device, which comprises a priming charge to which a primer is coupled, the firing of which is dependent on a control signal. The characteristics of the initiating charge determine the profile of the detonation wave in the explosive charge as well as its isochronism. Under the action of the detonation products located immediately behind the detonation wave, the metallic coating of the cavity is set in motion and projects on the axis of symmetry of the hollow charge. The result is a metallic projectile composed, on the one hand, of a metal jet animated at the head with a considerable speed which can reach 10 000 ms -1 , and on the other hand, of a metallic core animated with a speed more moderate, of the order of a few hundred meters / second. These two components, resulting from the implosion of the metallic coating of the cavity, both translate on the axis of symmetry of the hollow charge. The passage of the perforating jet in a massive body leaves a crater of great depth and a relatively small diameter, while the metal core whose significant mass is a disturbing element which tends to block the hole left by the passage of the metal spray.

Les applications courantes des charges creuses sont largement connues, surtout dans l'art militaire où elles sont utilisées pour perforer les blindages de protection des objectifs, notamment des véhicules de combat, mais elles trouvent également des applications dans le domaine civil pour la perforation des tubages des sondages pétrolifères, ainsi que le ciment disposé, le cas échéant derrière le tubage, et les matériaux géologiques situés derrière le ciment.The common applications of shaped charges are widely known, especially in the military art where they are used for perforate the protective armor of objectives, in particular combat vehicles, but they also find applications in the civil field for the perforation of casings of oil drilling, as well as the cement placed, if necessary behind the casing, and geological materials located behind the cement.

Dans les applications précitées des charges creuses, il se pose le problème de réaliser des "trous clairs" c'est à dire des trous qui ne soient pas obturés par le noyau métallique qui se translate à l'arrière du jet perforant.In the aforementioned applications of hollow charges, the problem arises of making "clear holes", that is to say holes which are not blocked by the metal core which translates at the rear of the perforating jet.

Le problème de la perforation d'un trou clair dans un corps massif à l'aide d'une charge creuse, a déjà reçu des solutions. En effet, on a déjà proposé et réalisé des charges creuses ayant un revêtement bimétallique, ou selon une variante, un revêtement constitué de poudres métalliques frittées. Dans le cas des revêtements bimétalliques, la partie du revêtement qui génère le noyau métallique est constitué par un métal qui se consume dans l'air. Dans le cas d'un revêtement en matériau fritté, le noyau métallique est pulvérisé et se désagrège après sa formation. Ces résultats sont obtenus au détriment des performances de perforation de la charge creuse.The problem of perforating a clear hole in a solid body using a hollow charge has already been solved. In fact, hollow charges have already been proposed and produced having a bimetallic coating, or according to a variant, a coating consisting of sintered metal powders. In the case of bimetallic coatings, the part of the coating which generates the metal core consists of a metal which is consumed in the air. In the case of a coating made of sintered material, the metal core is pulverized and disintegrates after its formation. These results are obtained at the expense of perforation performance of the shaped charge.

Dans les applications des charges creuses mises en oeuvre dans les missiles guidés destinés à l'interception et la destruction de cibles blindées, on recherche une caractéristique complémentaire qui est de créer un jet perforant de longueur aussi importante que possible et dont la fragmentation apparait tardivement. Cette caractéristique permet de placer la charge creuse dans une section arrière du missile tout en conservant une efficacité élevée de perforation, contre des cibles comportant des plaques de pré- blindage.In the applications of the shaped charges used in guided missiles intended for the interception and destruction of armored targets, an additional characteristic is sought which is to create a piercing jet of as great a length as possible and whose fragmentation appears late. This characteristic makes it possible to place the hollow charge in a rear section of the missile while retaining a high perforation efficiency, against targets comprising pre-armor plates.

Dans le but de fournir des solutions plus satisfaisantes aux problèmes précités, qui sont rencontrés lors de la réalisation de charges creuses perforantes, la Demanderesse à entrepris un programme de recherches afin de dégager l'influence des divers paramètres de construction de la charge et d'obtenir des combinaisons optimales de ces paramètres afin de réaliser un pouvoir perforant conventionnel au moins égal à celui des charges creuses de l'état de la technique et néanmoins peu dépendant de la distance d'action, ou distance de "Stand-off", jusqu'à des valeurs de celle-ci atteignant 10 fois le calibre de la charge creuse.In order to provide more satisfactory solutions to the aforementioned problems, which are encountered during the production of perforating hollow charges, the Applicant has undertaken a research program in order to identify the influence of the various parameters of charge construction and get combinations optimum of these parameters in order to achieve a conventional perforating power at least equal to that of the hollow charges of the state of the art and nevertheless not very dependent on the distance of action, or distance of "Stand-off", up to its values reaching 10 times the rating of the shaped charge.

Pour remédier aux inconvénients précités des charges creuses perforantes de l'état de la technique, une charge creuse destinée au percement d'un trou clair dans un corps massif monolithique ou composite, comprend un chargement explosif de révolution dans lequel est ménagée une cavité ouverte ayant un revêtement métallique, et un chargement d'amorçage, en vue de produire un projectile métallique composé d'un jet perforant et d'un noyau ; dans le but d'imprimer au noyau métallique une vitesse sensiblement nulle, ou préférentiellement opposée à la direction de déplacement du jet perforant, le rayon de courbure du profil de la cavité croît progressivement en fonction de la distance du sommet à la base de la cavité.To remedy the aforementioned drawbacks of perforating hollow charges of the state of the art, a hollow charge intended for drilling a clear hole in a solid monolithic or composite body, comprises an explosive charge of revolution in which an open cavity is formed having a metallic coating, and a priming charge, to produce a metallic projectile composed of a piercing jet and a core; in order to impart a substantially zero speed to the metal core, or preferably opposite to the direction of movement of the perforating jet, the radius of curvature of the profile of the cavity gradually increases as a function of the distance from the top to the base of the cavity .

Selon une caractéristique complémentaire, l'épaisseur du revêtement métallique de la cavité croît progressivement en fonction de la distance du sommet à la base de la cavité.According to an additional characteristic, the thickness of the metal coating of the cavity gradually increases as a function of the distance from the top to the base of the cavity.

Selon une autre caractéristique le chargement d'amorçage comprend un conformateur afin d'amorcer une onde de détonation annulaire, telle que les forces de pression appliquée sur la face externe du revêtement métallique soient perpendiculaires à cette surface ; dans ce conformateur, un élément cylindrique métallique est disposé axialement, la fonction de cet élément cylindrique étant de dévier radialement l'onde d'amorçage sans que la puissance de l'onde de détonation ne soit aucunement diminuée.According to another characteristic, the priming charge comprises a shaping device in order to initiate an annular detonation wave, such that the pressure forces applied to the external face of the metallic coating are perpendicular to this surface; in this shaper, a metallic cylindrical element is disposed axially, the function of this cylindrical element being to deflect the initiating wave radially without the power of the detonation wave being in any way diminished.

D'autres caractéristiques apparaîtront dans la description détaillée, d'une charge creuse perforante réalisée conformément à l'invention, faite en regard de dessins annexés, sur ces dessins :

  • - la figure 1 est une vue longitudinale simplifiée d'un missile autoguidé équipé d'une charge creuse selon l'invention et,
  • - la figure 2 est une vue en coupe d'une forme de réalisation de la charge creuse perforante.
Other characteristics will appear in the detailed description of a perforating hollow charge produced in accordance with the invention, made with reference to the appended drawings, in these drawings:
  • FIG. 1 is a simplified longitudinal view of a self-guided missile equipped with a hollow charge according to the invention and,
  • - Figure 2 is a sectional view of an embodiment of the perforating hollow charge.

La figure 1 représente, sous une forme schématique, un missile autoguidé équipé d'une charge creuse perforante réalisée conformément à l'invention. Ce missile d'axe longitudinal XX' est défini par ses dimensions physiques : son diamètre, ou calibre øp ; sa longueur hors-tout Lp, la distance Dg de son centre de gravité G et la distance De de la charge creuse par rapport à l'extrémité de son ogive. Ce missile autoguidé comprend les principales sections suivantes :

  • - une section de pilotage B, laquelle est centrée sur le centre de gravité G et comprend un impulseur capable de créer une force de poussée transverse ; cet impulseur est constitué d'un générateur de gaz symétrique 1 qui alimente, au moins, une tuyère latérale 2.
  • - une section de guidage A, laquelle est adjacente à la partie avant de la section de pilotage B et est terminée par une ogive transparente aux ondes optiques, à l'arrière du dôme optique 3 sont disposés les composants optiques et électrooptiques d'un autodirecteur 4 destiné à l'acquisition et à la poursuite de l'image de la cible visée, les circuits électroniques associés à l'autodirecteur et au dispositif de pilotage sont disposés dans un compartiment 5.
  • - une section de la charge militaire C, laquelle est adjacente à la partie arrière de la section de pilotage B, cette section renferme : une charge creuse 6, comportant une cavité creuse 7 ayant un revêtement métallique 8, et des circuits de sécurité et d'armement de la charge creuse, celle-ci étant disposée coaxialement à l'axe longitudinal XX'.
FIG. 1 represents, in a schematic form, a self-guided missile equipped with a perforating hollow charge produced in accordance with the invention. This missile with a longitudinal axis XX ′ is defined by its physical dimensions: its diameter, or caliber ø p ; its overall length Lp, the distance Dg from its center of gravity G and the distance De from the hollow charge with respect to the end of its warhead. This guided missile includes the following main sections:
  • - a control section B, which is centered on the center of gravity G and comprises an impeller capable of creating a transverse thrust force; this impeller consists of a symmetrical gas generator 1 which supplies, at least, a side nozzle 2.
  • - a guide section A, which is adjacent to the front part of the piloting section B and is terminated by an ogive transparent to optical waves, at the rear of the optical dome 3 are arranged the optical and electro-optical components of a seeker 4 intended for the acquisition and the pursuit of the image of the targeted target, the electronic circuits associated with the seeker and the piloting device are arranged in a compartment 5.
  • a section of the military charge C, which is adjacent to the rear part of the piloting section B, this section contains: a hollow charge 6, comprising a hollow cavity 7 having a metallic coating 8, and safety and security circuits arming of the hollow charge, the latter being arranged coaxially to the longitudinal axis XX '.

De plus, un canal central 9, destiné a fournir un libre passage au jet de métal projeté par la charge creuse, traverse axialement le générateur de gaz de l'impulseur 1 et le compartiment 5 des circuits électroniques et débouche à l'arrière des composants optiques de la tête de guidage, tandis que l'extrémité opposée de ce canal central débouche, en s'évasant sur la base de la cavité de la charge creuse. Il est important de noter que la dimension axiale x de la partie évasée du canal central doit être minimisée, ce qui implique que le jet de métal doit converger rapidement dès sa formation.In addition, a central channel 9, intended to provide a free passage for the metal jet projected by the hollow charge, axially passes through the gas generator of the impeller 1 and the compartment 5 of the electronic circuits and opens out at the rear of the components. optics of the guide head, while the opposite end of this central channel opens, flaring on the base of the hollow charge cavity. It is important to note that the axial dimension x of the part flaring of the central channel must be minimized, which implies that the metal jet must converge quickly as soon as it forms.

La figure 2 est une vue en coupe longitudinale d'une charge creuse perforante conforme à l'invention et plus particulièrement adaptée à une application à un missile autoguidé tel que décrit ci- dessus ; cette charge creuse comprend les éléments suivants :

  • - un chargement d'un explosif puissant, dit chargement principal 10, dans lequel une cavité ouverte 11 est en contact intime avec un revêtement métallique 12 ; ce chargement principal, de révolution autour de l'axe de symétrie de la charge creuse, est placé à l'intérieur d'un élément cylindrique 13 qui participe au confinement de l'onde de détonation vers la surface externe du revêtement métallique.
  • - un dispositif d'amorçage qui comprend un chargement d'amorçage 16 et un boitier de sécurité et d'armement 17 incluant une amorce, non représentée. Le chargement d'amorçage, dit chargement auxiliaire, est de forme cylindro-conique et comporte axialement un conformateur 14, également de forme cylindro-conique, dont la fonction est d'assurer un amorçage annulaire de l'onde de détonation du chargement principal ; de plus, le conformateur s'encastre très faiblement dans le chargement principal. A la partie arrière du conformateur, un élément métallique 20 de forme cylindrique est disposé axialement ; sa fonction est de dévier radialement l'onde d'amorçage sans que la puissance de l'onde de détonation de la charge creuse soit diminuée. Enfin, le dispositif d'amorçage est muni d'un capot 18 qui s'emboite de façon précise sur l'élément cylindrique 13 du chargement principal afin d'assurer un centrage correct des deux chargements. Le contact intime des sections en regard des chargements principal et auxiliaire est renforcé par l'action d'une bague de serrage 17 située à la jonction du capot 17 et de l'élément cylindrique 13. On peut également noter que les sections de contact des deux chargements ont un diamètre 0 p égal et supérieur au diamètre 0 c de la partie du chargement principal 10 entourant la cavité 11 dans le but de créer une onde annulaire qui favorise l'obtention d'une longueur importante du jet perforant.
Figure 2 is a longitudinal sectional view of a perforating hollow charge according to the invention and more particularly adapted to an application to a guided missile as described above; this shaped charge comprises the following elements:
  • - A charge of a powerful explosive, called main charge 10, in which an open cavity 11 is in intimate contact with a metallic coating 12; this main charge, of revolution around the axis of symmetry of the hollow charge, is placed inside a cylindrical element 13 which participates in the confinement of the detonation wave towards the external surface of the metallic coating.
  • - a priming device which comprises a priming charge 16 and a safety and arming unit 17 including a primer, not shown. The priming charge, called auxiliary charge, is of cylindro-conical shape and comprises axially a conformator 14, also of cylindro-conical shape, the function of which is to ensure an annular priming of the detonation wave of the main charge; in addition, the shaper fits very weakly into the main load. At the rear part of the former, a metallic element 20 of cylindrical shape is arranged axially; its function is to radially deflect the priming wave without the power of the detonation wave of the hollow charge being reduced. Finally, the initiation device is provided with a cover 18 which fits precisely on the cylindrical element 13 of the main load in order to ensure correct centering of the two loads. The intimate contact of the sections opposite the main and auxiliary loads is reinforced by the action of a clamping ring 17 located at the junction of the cover 17 and the cylindrical element 13. It may also be noted that the contact sections of the two loads have a diameter 0 p equal to and greater than the diameter 0 c of the part of the main load 10 surrounding the cavity 11 in order to create an annular wave which promotes obtaining a significant length of the perforating jet.

Le profil de la cavité ouverte 11 est l'un des paramètres de construction de la charge creuse qui gouverne la formation d'un noyau métallique animée d'une vitesse sensiblement nulle, ou préférentiellement négative, c'est à dire de direction opposée à celle du jet perforant. Pour obtenir cet effet, le rayon de courbure Rc de la cavité doit croître progressivement depuis le sommet de la cavité jusqu'à sa base. Cette loi de variation du rayon de courbure de la cavité lui confère un profil de forme sensiblement hyperbolique dont une forme typique est la forme en "TULIPE", c'est à dire que la relation entre la distance radiale Y et la distance axiale x de la cavité est de la forme :

Figure imgb0001
avec O ≤x (xp et xp est la profondeur de la cavité.The profile of the open cavity 11 is one of the parameters of construction of the hollow charge which governs the formation of a metallic core animated with a substantially zero speed, or preferentially negative, that is to say in a direction opposite to that of the piercing jet. To obtain this effect, the radius of curvature Rc of the cavity must gradually increase from the top of the cavity to its base. This law of variation of the radius of curvature of the cavity gives it a substantially hyperbolic shape profile, a typical shape of which is the "TULIP" shape, that is to say that the relationship between the radial distance Y and the axial distance x of the cavity is of the form:
Figure imgb0001
 with O ≤x (xp and xp is the depth of the cavity.

Les grandeurs des coefficients A.B et C dépendent des dimensions physiques de la charge creuse, notamment de son calibre øp, des trajets de l'onde de détonation dans le chargement principal, mais également de la nature du matériau explosif utilisé. La profondeur xp de la cavité est alors sensiblement supérieure à son ouverture ør, tandis que le diamètre øc du chargement explosif est supérieur à l'ouverture ør de la cavité, de façon à disposer d'une certaine épaisseur d'explosif, de l'ordre de quelques mm, autour de la base de la cavité.The magnitudes of the coefficients AB and C depend on the physical dimensions of the shaped charge, in particular its caliber ø p , the paths of the detonation wave in the main charge, but also on the nature of the explosive material used. The depth xp of the cavity is then substantially greater than its opening ø r , while the diameter ø c of the explosive charge is greater than the opening ø r of the cavity, so as to have a certain thickness of explosive, of the order of a few mm, around the base of the cavity.

Les performances de perforation de la charge creuse peuvent encore être améliorées, si conjointement, l'épaisseur e du revêtement métallique croit progressivement du sommet vers la base de la cavité selon une relation de la forme :

Figure imgb0002
avec eo de l'ordre de 0, 06 O et e (Xp) sensiblement égale à O, 025 øcC.The perforation performance of the hollow charge can be further improved, if together, the thickness e of the metal coating gradually increases from the top to the base of the cavity according to a relation of the form:
Figure imgb0002
 with eo of the order of 0.06 O and e (Xp) substantially equal to 0.025 øc C.

Pour cette configuration de la charge creuse, la distance de dégagement x c devant l'ouverture de la cavité, comme représentée sur la figure 1, est relativement faible, de l'ordre de 0,06 øc, ce qui réduit sensiblement l'encombrement longitudinal de la charge creuse et, par voie de conséquence, celui de la charge militaire C.For this configuration of the hollow charge, the clearance distance x c in front of the opening of the cavity, as shown in Figure 1, is relatively small, of the order of 0.06 ø c , which significantly reduces the longitudinal dimensions of the hollow charge and, consequently, that of the military charge C.

Les autres paramètres de la charge creuse, qui sont plus particulièrement associés au dispositif d'amorçage de l'onde de détonation du chargement explosif doivent être pris en compte puisque leur influence sur le profil et l'isochronisme de l'onde de détonation est importante, et notamment, si l'on considère l'amorçage annulaire de l'onde de détonation.The other parameters of the hollow charge, which are more particularly associated with the device for initiating the detonation wave of the explosive charge must be taken into account since their influence on the profile and the isochronism of the detonation wave is significant. , and in particular, if we consider the annular initiation of the detonation wave.

La charge creuse qui vient d'être décrite en détail présente une configuration suffisamment simple pour optimiser les valeurs des paramètres et atteindre les performances de perforation nécessaires. D'autre part, il est important de noter que les précautions habituelles en la matière doivent être observées : homogénéité et propriétés physiques des matériaux de construction, et parfaite symétrie de révolution des composants de la charge creuse. Les moyens de sécurité, d'armement et de mise à feu, par exemple du type inertiel, qui sont connus en soi et sans influence sur l'invention ne sont donc pas décrits ici.The shaped charge which has just been described in detail has a configuration which is simple enough to optimize the values of the parameters and achieve the necessary perforation performance. On the other hand, it is important to note that the usual precautions in this area must be observed: homogeneity and physical properties of the building materials, and perfect symmetry of revolution of the components of the hollow charge. The security, arming and firing means, for example of the inertial type, which are known per se and have no influence on the invention are therefore not described here.

Pour une charge creuse perforante destinée à un missile autoguidé d'un calibre Op de 100mm, les poids respectifs de l'explosif principal et du revêtement métallique sont d'environ 800g et 200g. A titre indicatif, le chargement principal et le chargement auxiliaire peuvent être constitués par un composite à l'octogone ; le revêtement métallique de la cavité peut être réalisé en un métal tel que le cuivre ; le conformateur est construit en un matériau plastique ou encore en un matériau végétal, tel que le bois ; enfin l'élément cylindrique métallique, inclus dans le conformateur, est réalisé en un matériau métallique dense et préférentiellement en acier.For a perforating hollow charge intended for a guided missile with an Op caliber of 100mm, the respective weights of the main explosive and of the metallic coating are approximately 800g and 200g. As an indication, the main load and the auxiliary load can be constituted by an octagon composite; the metallic coating of the cavity can be made of a metal such as copper; the conformator is constructed of a plastic material or else of a vegetable material, such as wood; finally the metallic cylindrical element, included in the shaper, is made of a dense metallic material and preferably of steel.

A titre illustratif, les performances comparées d'une charge creuse dite en "TULIPE" selon l'invention et d'une charge creuse classique, dite en "trompette" sont résumées dans le tableau unique annexé ci-après.

  • - en (a), on voit que l'encombrement effectif de la charge creuse en tulipe est sensiblement plus faible, du fait que la distance xc = K 0c du dégagement en avant de la cavité est réduite.
  • - en (b), on peut noter que le noyau métallique N résultant de l'implosion du revêtement métallique de la cavité a une vitesse de déplacement V N opposée à la vitesse de translation VJ du jet de métal fourni par ce revêtement métallique ; il en résulte que le trou, provoqué par le passage du jet de métal au travers du blindage, reste clair.
  • - en (c), les courbes représentées montrent le pouvoir de perforation normalisé Pp/Øc des deux charges creuses considérées en fonction de la distance d'action normalisée Da/Øc; le pouvoir de perforation d'un blindage classique est sensiblement du même ordre de grandeur pour les deux types de charges creuses, toutefois il faut noter que la distance d'action Da/Øc , au delà de laquelle apparaît le phénomène de fragmentation du jet métallique est notablement en faveur de la charge creuse en tulipe, il résulte de cette dernière caractéristique que ce type de charge creuse est particulièrement performant, quand il est mis en oeuvre en vue de la perforation de blindages de grande épaisseur apparente, tels que ceux constitués par des plaques étagées, qu'ils comportent ou non des éléments dispersifs intercalaires.
By way of illustration, the comparative performances of a shaped charge known as a "TULIP" according to the invention and a shaped charge classical, called "trumpet" are summarized in the single table annexed below.
  • - In (a), we see that the effective size of the hollow tulip charge is significantly smaller, because the distance xc = K 0 c of the clearance in front of the cavity is reduced.
  • - In (b), it can be noted that the metal core N resulting from the implosion of the metal coating of the cavity has a displacement speed V N opposite to the translation speed V J of the metal jet supplied by this metal coating; as a result, the hole, caused by the passage of the metal jet through the shielding, remains clear.
  • - In (c), the curves shown show the normalized perforation power Pp / Ø c of the two hollow charges considered as a function of the normalized action distance Da / Ø c ; the perforation power of a conventional shielding is roughly of the same order of magnitude for the two types of shaped charges, however it should be noted that the action distance Da / Ø c , beyond which appears the phenomenon of fragmentation of the jet metallic is notably in favor of the hollow charge in tulip, it results from this last characteristic that this type of hollow charge is particularly efficient, when it is used for the perforation of shieldings of great apparent thickness, such as those formed by stepped plates, whether or not they include intermediate dispersive elements.

Les performances comparées d'une charge creuse perforante selon l'invention et d'une charge creuse classique ont été confirmées par l'analyse des résultats fournis lors d'expérimentations réalisées sur des bases d'essais et ces expérimentations montrent que les résultats relevés sont parfaitement reproductibles.The comparative performances of a perforating hollow charge according to the invention and of a conventional hollow charge were confirmed by the analysis of the results provided during experiments carried out on test bases and these experiments show that the results noted are perfectly reproducible.

On voit maintenant plus clairement, les avantages que procure une charge creuse perforante réalisée conformément à l'invention : l'obtention d'un trou parfaitement clair, et une distance d'action élevée, laquelle qui contribue au pouvoir perforant du jet de matière et permet conjointement de placer la charge militaire à l'arrière des projectiles.We now see more clearly, the advantages of a perforating hollow charge produced in accordance with the invention: obtaining a perfectly clear hole, and a high action distance, which contributes to the perforating power of the material jet and allows the military charge to be placed behind the projectiles.

Lorsque le résultat recherché est limité seulement à l'obtention d'un trou clair et que la distance d'action est réduite comme dans les applications aux sondages pétrolifères, la construction de la charge creuse peut-être simplifiée, notamment, l'épaisseur du revêtement métallique de la cavité peut être maintenue constante ; le conformateur inclus dans le chargement d'amorçage peut être éliminé, ou tout au moins simplifié, et les sections de contact des deux chargements peuvent avoir un diamètre égal à celui de la charge creuse.When the desired result is limited only to obtaining a clear hole and the action distance is reduced as in applications for oil drilling, the construction of the shaped charge may be simplified, in particular, the thickness of the metal lining of the cavity can be kept constant; the conformator included in the priming charge can be eliminated, or at least simplified, and the contact sections of the two charges can have a diameter equal to that of the shaped charge.

Une charge creuse, selon l'invention, trouve son application dans l'art militaire, mais également dans les sondages pétrolifères et le percement de trous de profondeur important dans les couches de charbon.

Figure imgb0003
A hollow charge, according to the invention, finds its application in the military art, but also in oil drilling and the drilling of holes of great depth in the coal layers.
Figure imgb0003

Claims (5)

1. Charge creuse destinée au percement d'un trou clair dans un corps massif ou composites, cette charge comprenant essentiellement, un chargement explosif (10) de révolution dans lequel est inclue une cavité ouverte (11) ayant un revêtement métallique (12), et un chargement d'amorçage (16) pour créer un projectile métallique composé d'un jet perforant (J) et d'un noyau (N), caractérisée en ce que dans le but d'imprimer au noyau une vitesse nulle, ou préférentiellement opposée à celle du jet perforant, le rayon de courbure (Rc) du profil de la cavité croit progressivement en fonction de la distance (x) du sommet à la base de la cavité.1. Hollow charge intended for piercing a clear hole in a solid or composite body, this charge essentially comprising an explosive charge (10) of revolution in which an open cavity (11) having a metallic coating (12) is included, and a priming charge (16) to create a metallic projectile composed of a perforating jet (J) and a core (N), characterized in that for the purpose of imparting zero speed to the core, or preferably opposite to that of the perforating jet, the radius of curvature (Rc) of the profile of the cavity gradually increases as a function of the distance (x) from the top to the base of the cavity. 2. Charge creuse selon la revendication 1, caractérisée en ce que le profil de la cavité ouverte (11) incluse dans le chargement explosif (10) a une forme en "tulipe".2. Hollow charge according to claim 1, characterized in that the profile of the open cavity (11) included in the explosive charge (10) has a "tulip" shape. 3. Charge creuse selon les revendications 1 ou 2, caractérisée en ce que le revêtement métallique (12) de la cavité ouverte (11) à une épaisseur (e) qui croît progressivement en fonction de la distance (x) du sommet à la base de la cavité selon une relation :
Figure imgb0004
 3. Hollow charge according to claims 1 or 2, characterized in that the metallic coating (12) of the open cavity (11) has a thickness (e) which increases progressively as a function of the distance (x) from the top to the base of the cavity according to a relation:
Figure imgb0004
 4. Charge creuse selon l'une des revendications précédentes, caractérisée en ce que le chargement d'amorçage (16) inclut un élément conformateur (14) de révolution qui comporte dans sa partie axiale un élément cylindrique métallique (20) destiné à dévier radialement l'onde d'amorçage du chargement explosif.4. Hollow charge according to one of the preceding claims, characterized in that the priming charge (16) includes a shaping element (14) of revolution which comprises in its axial part a metallic cylindrical element (20) intended to deflect radially the initiating wave of the explosive charge. 5. Charge creuse selon la revendication 4, caractérisée en ce que le diamètre Øp des sections de contact du chargement explosif (10) et du chargement d'amorçage (16) est supérieur au diamètre (Øc)de la partie du chargement explosif entourant la cavité.5. Hollow charge according to claim 4, characterized in that the diameter Ø p of the contact sections of the explosive charge (10) and of the initiating charge (16) is greater than the diameter (Ø c ) of the part of the explosive charge surrounding the cavity.
EP83400675A 1982-04-02 1983-03-31 Armour-piercing hollow charge Withdrawn EP0091860A1 (en)

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FR8205784 1982-04-02
FR8205784 1982-04-02

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0150241A1 (en) * 1984-01-28 1985-08-07 Oy Hackman AB Hollow charge with directed explosive effect
GB2163535A (en) * 1984-08-21 1986-02-26 Serat Hollow charges
FR2581747A1 (en) * 1985-05-07 1986-11-14 Serat IMPROVEMENTS TO HOLLOW LOADS
US4829901A (en) * 1987-12-28 1989-05-16 Baker Hughes Incorporated Shaped charge having multi-point initiation for well perforating guns and method
DE4119586A1 (en) * 1990-07-31 1992-02-06 Messerschmitt Boelkow Blohm Hollow charge partic. for armour piercing ammunition
NL1009398C2 (en) * 1997-06-13 2000-03-22 Western Atlas Int Composite profile load with high performance.
EP2410283A3 (en) * 2010-07-19 2014-10-01 Diehl BGT Defence GmbH & Co.KG Warhead

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1037819A (en) * 1951-05-29 1953-09-23 Soc Tech De Rech Ind Improvements to shaped charges
FR1199923A (en) * 1957-07-18 1959-12-17 Prb Nv Improved shaped charge
FR76926E (en) * 1959-01-14 1961-12-15 Borg Warner Improvements made to explosive charges
FR2216544A1 (en) * 1973-02-02 1974-08-30 Luchaire Sa
FR2308906A1 (en) * 1975-04-23 1976-11-19 Luchaire Sa Hollow explosive charge fuse - has air chamber between priming charge and apex of hollow charge sheathing
FR2308903A1 (en) * 1975-04-26 1976-11-19 Diehl Mortar bomb having target guidance system - with shrapnel-forming shell and explosive charge and separate propellant charges
FR2341124A1 (en) * 1976-02-12 1977-09-09 Rheinmetall Gmbh PERFORATING TANDEM PROJECTILE, ESPECIALLY FOR FIGHTING PARTITIONED TARGETS, MULTI-THICKNESS ARMORING

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1037819A (en) * 1951-05-29 1953-09-23 Soc Tech De Rech Ind Improvements to shaped charges
FR1199923A (en) * 1957-07-18 1959-12-17 Prb Nv Improved shaped charge
FR76926E (en) * 1959-01-14 1961-12-15 Borg Warner Improvements made to explosive charges
FR2216544A1 (en) * 1973-02-02 1974-08-30 Luchaire Sa
FR2308906A1 (en) * 1975-04-23 1976-11-19 Luchaire Sa Hollow explosive charge fuse - has air chamber between priming charge and apex of hollow charge sheathing
FR2308903A1 (en) * 1975-04-26 1976-11-19 Diehl Mortar bomb having target guidance system - with shrapnel-forming shell and explosive charge and separate propellant charges
FR2341124A1 (en) * 1976-02-12 1977-09-09 Rheinmetall Gmbh PERFORATING TANDEM PROJECTILE, ESPECIALLY FOR FIGHTING PARTITIONED TARGETS, MULTI-THICKNESS ARMORING

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0150241A1 (en) * 1984-01-28 1985-08-07 Oy Hackman AB Hollow charge with directed explosive effect
GB2163535A (en) * 1984-08-21 1986-02-26 Serat Hollow charges
US4672896A (en) * 1984-08-21 1987-06-16 Societe D'etudes, De Realisations Et D'applications Techniques Hollow charges
FR2581747A1 (en) * 1985-05-07 1986-11-14 Serat IMPROVEMENTS TO HOLLOW LOADS
GB2175072A (en) * 1985-05-07 1986-11-19 Serat Hollow charges
US4829901A (en) * 1987-12-28 1989-05-16 Baker Hughes Incorporated Shaped charge having multi-point initiation for well perforating guns and method
DE4119586A1 (en) * 1990-07-31 1992-02-06 Messerschmitt Boelkow Blohm Hollow charge partic. for armour piercing ammunition
NL1009398C2 (en) * 1997-06-13 2000-03-22 Western Atlas Int Composite profile load with high performance.
EP2410283A3 (en) * 2010-07-19 2014-10-01 Diehl BGT Defence GmbH & Co.KG Warhead

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