EP0438343B1 - Penetrator ammunition for targets with high mechanical resistance - Google Patents

Abstract

The invention concerns a perforating munition for targets possessing high mechanical strength. A perforating munition, released at very low altitude to prevent destruction by ground-air defense systems, possesses a braking system constituted by a parachute (24) to give the velocity vector of the munition a position that is as close as possible to the vertical, thus enabling an improvement in the effectiveness of the munition on impact. To improve the positioning of the velocity vector with respect to the vertical, the munition has a curvature correction device comprising a back projector (13) that is fixedly joined to the rear part (2) of the munition and is positioned in a ring-like way around a front part (1) of the munition, so as to reduce the curvature of the munition in order to increase the effectiveness of the munition.

Description

The invention relates to a perforating ammunition for high mechanical resistance targets.

• V_o : vitesse de la munition en fin de freinage ;
• V : vitesse de la munition en fin de propulsion ;
• T : temps de combustion du propulseur ;
• i : angle d'incidence qui est l'angle du vecteur vitesse par rapport à la cible avec la verticale de la cible placé à l'horizontal

et que ces paramètres sont déterminés de manière à avoir, par exemple, une vitesse d'impact V = 350 m/s et un temps de combustion qu'on ne sait pas rendre inférieur à 0,2 s, dans l'état actuel de la technique et compte tenu des contraintes géométriques imposées, la longueur de la trajectoire propulsée sera d'environ 35 m c'est-à-dire qu'il faut allumer la propulsion à une altitude d'au moins Z = 40 m. D'autre part, la munition doit avoir en fin de la phase de freinage F, une attitude proche de la verticale, par exemple une incidence i = 15°, après une chute balistique égale à la différence entre l'altitude de largage et celle de l'allumage de la propulsion c'est-à-dire, dans les conditions choisies précédemment, l'altitude de largage étant de 75 m, qu'on ne dispose que de 35 m pour obtenir l'attitude souhaitée. Pour obtenir ce résultat, il faut utiliser un système de freinage, par exemple, un parachute positionné à l'arrière de la munition dont les dimensions et la robustesse seraient incompatibles avec l'espace disponible.Perforating ammunition for, for example, concrete runways is generally placed inside an aerial vehicle called a cargo ship which must fly over the objective at very low altitude and at very high speed. Indeed, to avoid the risks of destruction of the air vehicle by opposing ground-air defenses, the air vehicle has an altitude of the order of 75 m and a speed of the order of 300 m / s. The aerial vehicle ejects, at a determined moment to reach the desired objective, the various munitions with a high horizontal speed and in a horizontal attitude parallel to the plane containing the target as shown in FIG. 1. Each of the munitions M, at the end of trajectory, must have, at impact I, a speed vector as close as possible to the vertical, to facilitate the complete penetration of the ammunition into the target before the final explosion. The munition therefore has an incidence defined as being the angle of the speed vector with respect to the target with the vertical of the target placed horizontally. For this, each of the munitions has a braking phase F and an acceleration phase A making it possible to respectively give the munition an orientation and a speed necessary for the operation of a piercing ammunition for the deterioration of a concrete track. The ammunition acceleration phase must be triggered at a sufficient altitude Z for the end of the propulsion to occur before impact. Knowing that this altitude is determined as a function of a length 1 of the powered trajectory defined by: 1 = V + V o 2 . T. cos i or

• V _o : speed of the ammunition at the end of braking;
• V: speed of the munition at the end of propulsion;
• T: combustion time of the propellant;
• i: angle of incidence which is the angle of the speed vector relative to the target with the vertical of the target placed horizontally

and that these parameters are determined so as to have, for example, an impact speed V = 350 m / s and a combustion time which it is not known to make less than 0.2 s, in the current state of the technique and taking into account the geometrical constraints imposed, the length of the propelled trajectory will be approximately 35 m, that is to say that the propulsion must be started at an altitude of at least Z = 40 m. On the other hand, the ammunition must have at the end of the braking phase F, an attitude close to vertical, for example an incidence i = 15 °, after a ballistic fall equal to the difference between the release altitude and that the ignition of the propulsion, that is to say, under the conditions chosen above, the drop altitude being 75 m, that only 35 m are available to obtain the desired attitude. To obtain this result, a braking system must be used, for example, a parachute positioned at the rear of the ammunition, the dimensions and robustness of which would be incompatible with the space available.

There are many munitions intended to perforate and deteriorate surfaces with high mechanical resistance. These ammunition whose effectiveness depends on a large number of parameters (penetration depth, amount of charge explosive, ...) are generally dropped at very low altitude of an air vehicle with imposed dimensions determining a volume in which the ammunition must be housed. This air vehicle having a determined size, it limits the number and the size of the modules contained inside the ammunition perforating. To ensure the performance of such ammunition, it is necessary to position the greatest number of modules possible inside the ammunition. For this, it is therefore necessary to find munition architecture to make the best use of available space.

We know from document DE B 1 578 089 ammunition ground-to-ground with aerodynamic braking and parachute, according to the document US A 2 693 327 a projectile slowing device, according to document US A 2,539,643 an air-sea torpedo, and according to document US A 4,573,412 a rocket penetrator, but none of these documents do not recommend means giving a piercing ammunition released horizontally at low altitude a trajectory allowing it to destroy a concrete track. Furthermore, we know from the document “Concrete dibber conceived in France” by R.R. Rodwell, Flight International - December 14, 1967 ammunition launched from an aerial vehicle with horizontal speed and attitude and intended to attack a target with horizontal development, said munition comprising a system of braking positioned at the rear of the ammunition, said braking system being equipped with a parachute, which when deployed, gives the trajectory of the ammunition a curvature as close as possible to the vertical, ammunition further comprising a back-propelling means positioned on the ammunition so as to reduce the curvature of the trajectory of the ammunition for increase the effectiveness of said munition by reducing its obliquity and a propulsion means then being put into service to increase the speed of the ammunition and thus penetrate the target.

The object of the invention is to remedy the aforementioned drawbacks by proposing a solution allowing the use of a braking system with acceptable dimensions.

The subject of the invention is a munition launched from an air vehicle with horizontal speed and attitude and intended to attack a horizontal development target, said munition comprising a system of braking positioned at the rear of the ammunition, said braking system being equipped with a parachute, which when deployed, gives the trajectory of the ammunition a first curvature as close as possible to the vertical, ammunition further comprising a back-propelling means positioned on the ammunition so as to reduce the first curvature of the trajectory of the ammunition obtained thanks to the parachute, which means of retropropulsion is ignited after deployment of the parachute, to increase the efficiency of said ammunition by reducing its obliquity, the back-propelling means being stopped at the end of the braking phase, and a propulsion means then being put in service to increase the speed of the ammunition and thus penetrate the target.

The invention also relates to a piercing munition comprising a front part formed by an envelope containing a charge explosive and a rear part, fixed to the front part by a means of fixing and comprising a set of modules ensuring operation ammunition, characterized in that at least one of the modules is placed annularly around part of the front part of the ammunition for limit the size of the ammunition by ensuring its effectiveness.

The present invention also relates to ammunition for target with high mechanical resistance, of the anti-track bomb type, capable of penetrate sufficiently even in very thick slabs.

For this purpose, it comprises at least one front part, containing an explosive charge, intended to penetrate the track ; according to the invention, the external surface of the part front has longitudinal grooves which have for function, on the one hand, to reduce the friction forces which oppose the entry into the track and, on the other hand, increase the transverse stiffness of the ammunition so as to reduce, during an oblique impact, the risk of flexion of the ammunition and ricochet thereof.

In a particular embodiment, the envelope of the front body is further made so that the splines form longitudinal hollow charges which pre-fracture, during the explosion, the concrete surrounding the front body.

• la figure 1 représente une courbure de la trajectoire selon l'art antérieur ;
• la figure 2 représente un schéma d'un mode de réalisation d'une munition perforante équipée d'un dispositif de correction de courbure de trajectoire selon l'invention ;
• la figure 3 représente une comparaison de courbure de trajectoire pour une munition perforante équipée ou non du dispositif selon l'invention.
• la figure 4 représente un schéma d'un mode de réalisation d'une munition perforante selon l'invention ;
• la figure 5 représente une variante de réalisation de la partie avant de la munition perforante selon l'invention ;
• la figure 6 représente un moyen de fixation de la partie avant de la munition à la partie arrière de la munition selon l'invention ;
• la figure 7 représente un schéma d'un mode de réalisation d'un système de fixation déverrouillable équipant la munition selon l'invention ;
• la figure 8 représente un schéma d'un mode d'intégration des munitions dans un cargo ;
• la figure 9 représente un schéma de fonctionnement d'un mode de réalisation d'une munition contre une piste en béton.
• la figure 10, le schéma d'un mode de réalisation de la munition selon l'invention ;
• la figure 11, une vue en coupe transversale de la munition représentée figure 10 ;
• la figure 12, une vue en coupe fractionnaire d'une variante de réalisation de la munition selon l'invention ;
• la figure 13, le schéma de variantes de réalisation de la munition selon l'invention.

The invention will be better understood with the aid of other explanations resulting from the following description, given by way of nonlimiting example and illustrated by the appended figures among which:

• FIG. 1 represents a curvature of the trajectory according to the prior art;
• FIG. 2 represents a diagram of an embodiment of a perforating ammunition equipped with a device for correcting trajectory curvature according to the invention;
• FIG. 3 represents a comparison of trajectory curvature for a piercing munition equipped or not with the device according to the invention.
• FIG. 4 represents a diagram of an embodiment of a piercing munition according to the invention;
• FIG. 5 represents an alternative embodiment of the front part of the piercing munition according to the invention;
• FIG. 6 represents a means of fixing the front part of the ammunition to the rear part of the ammunition according to the invention;
• FIG. 7 represents a diagram of an embodiment of an unlockable fixing system equipping the munition according to the invention;
• FIG. 8 represents a diagram of a mode of integration of the ammunition in a cargo ship;
• FIG. 9 represents a diagram of the operation of an embodiment of an ammunition against a concrete track.
• FIG. 10, the diagram of an embodiment of the munition according to the invention;
• Figure 11, a cross-sectional view of the munition shown in Figure 10;
• Figure 12, a fractional sectional view of an alternative embodiment of the munition according to the invention;
• Figure 13, the diagram of alternative embodiments of the ammunition according to the invention.

In these figure differences, the same references are relate to the same elements.

Figure 2 shows a first embodiment ammunition equipped with the device according to the invention.

This ammunition has two parts: a part front 1 intended to deteriorate a high resistance surface mechanical, for example a concrete track, or by entering it preferably over its entire length, either by crossing it and exploding below, and, a rear part 2 which may be, or no, with a diameter greater than that of the front part 1 and intended to provide a set of ballistic functions of the ammunition.

The front part 1 is, for example, in the form cylindrical. It consists of an envelope 3, by steel example, which ends at the front with a warhead 4, by conical example, and contains an explosive charge 5. Others elements can constitute the front part 1, for example a ballast respectively improving the power of penetration of the ammunition and shift the center of gravity ammunition or a priming rocket to fire the charge explodes and can be extended by a channel priming; these elements are not shown in the figure 1 and do not prevent the device from operating according to the invention. The front part 1 of the ammunition extends, in the embodiment example, inside the rear part 2 which thus covers it annularly.

A fastening system 6 holds the rear part 2 on the front part 1 so that the rear part 2 does not not oppose the penetration of the front part 1 into the track concrete. The rear part 2 comprises, among other things, a propellant 7 part of which can engage in space ring between front part 1 and rear part 2, a tail made up of fins 8 fixed for example on the periphery of a nozzle 9 positioned at the rear of the propellant 7 and a braking system comprising, for example, a box 10 inside which is placed a parachute 11 and fixed to the nozzle 9 of propellant 7, for example, by a system of unlockable mechanical fastener 12.

V :

vitesse de la munition

R :

rayon de courbure de la trajectoire

g :

accélération de la pesanteur

p :

pente de la vitesse

s :

abscisse curviligne

z :

altitude

on déduit une fonction F donnant la relation entre la variation de pente rapportée à la variation d'altitude et la vitesse et qui est : F = dpdz = gV2 tg p cette relation nous permet de dire qu'une diminution imposée au module de la vitesse de la munition se traduit par une augmentation de l'inclinaison du vecteur vitesse de la munition c'est-à-dire une diminution de l'incidence à l'impact. Les simulations montrent que pour une diminution donnée de V, l'incidence minimale est obtenue quand on allume la rétropropulsion à une date, donc à une abscisse, précise. Cette diminution de la vitesse ne doit pas être trop importante pour ne pas altérer l'efficacité du parachute.After the ammunition of an aerial vehicle containing several of these munitions is dropped, the ammunition follows a trajectory similar to the trajectory represented in FIG. 1. However, taking into account the dimension of the aerial vehicle containing the ammunition, the box 10 of the braking system has, for example, a square section to facilitate the storage of ammunition in the air vehicle. In this way the box 10 of dimensions greater than a box of circular section generally used, allows the parachute 11 contained inside the box 10 to have larger dimensions. This parachute 11 makes it possible to obtain, for example, an incidence of the order of 30 °. This incidence being too high, it suffices to operate during the trajectory of the munition a device for correcting the curvature of the trajectory according to the invention comprising a back-propelling means, for example, a back-propelling device 13 secured to the rear part 2 of ammunition. The back-propellant 13 is positioned, for example, at the front of the rear part 2 of the ammunition covering the front part 1 of said ammunition, in the annular space between the two front parts 1 and rear 2 and containing other elements contained in the rear part 2. The back-propellant 13 is provided, for example, with nozzles 14 through which the gases from combustion are ejected inside the propellant 13. These nozzles 14 are positioned, for example, so symmetrical about a longitudinal axis XX 'of the munition to provide thrust parallel to the axis XX' of the ammunition. This back-propellant 13 has characteristics which it is essential to define for this application. Indeed, certain elements of the propellant, such as, for example, an excessive thrust, an excessive combustion time and an ill-defined ignition moment, can disturb the trajectory and / or decrease or even cancel the correction effect of curvature of the ammunition, and thus, decrease the performance of the ammunition. To determine these elements, it suffices to know the following principle:
known relationships: . V 2 R = g cos p . R = ds dp . dz = ds sin p or :

V:

ammunition speed

A:

radius of curvature of the path

g:

gravity acceleration

p:

speed slope

s:

curvilinear abscissa

z:

altitude

we deduce a function F giving the relation between the slope variation compared to the altitude variation and the speed and which is: F = dp dz = g V 2 tg p this relation allows us to say that a reduction imposed on the modulus of the speed of the ammunition results in an increase in the inclination of the velocity vector of the ammunition i.e. a decrease in the incidence at impact. The simulations show that for a given decrease in V, the minimum incidence is obtained when the retropropulsion is switched on on a date, therefore on a precise abscissa. This reduction in speed must not be too great in order not to affect the efficiency of the parachute.

On the other hand, to avoid a pitch oscillation Too much amplitude caused by too fast rotation of the ammunition and causing the objective to be reached by the ammunition with too large an obliquity corresponding to the angle made between a longitudinal axis of the munition XX 'and the vector ammunition speed, the thrust given by the retropulsor can be spread over a relatively long time with a date earlier ignition.

FIG. 3 represents the comparison between the trajectory of a munition without back-propulsion SR and the trajectory of a munition with back-propulsion R. The slope p ₁ of the trajectory at an altitude z = 40 m is for example of the order of 60 ° (i ₁ = 30 °) when there is no back-drive and can go below 30 ° (i ₂ = 15 °) when there is back-drive.

The device according to the invention applies to armor-piercing ammunition for high resistance targets mechanical but it applies to all ammunition having a almost vertical impact with minimal impact difficult to obtain by the sole use of a parachute.

FIG. 4 represents the diagram of a first mode of production of the ammunition according to the invention. Ammunition has two parts: a front part 101 intended for deteriorate a surface with high mechanical resistance, by example a concrete track, preferably by entering it, along its entire length, either by crossing it and exploding in underside and a rear part 102 intended to ensure an assembly of ballistic functions of the ammunition. This rear part 102, integral with the front part 101, before the impact of the ammunition on the target, is detached at the time of impact so as not to slow down the penetration of the front part 101 in the target.

The front part 101 is, for example, in the form cylindrical. It consists of an envelope 103, by steel example, which ends at the front with a warhead 104, for example conical and at the rear for example by a rocket ignition device 105 placed behind an explosive charge 106 contained inside the envelope 103 and allowing trigger the charge explosion when the perforation is carried out, the initiation of the explosive charge being transmitted, by example at the front of the munition, by a priming channel 150 to increase the destructive power of the ammunition. The the outer surface of the envelope is, for example, smooth but it can be of any other form, for example formed of splines to, on the one hand, reduce friction forces during penetration and on the other hand increase the stiffness transverse of the ammunition to limit the bending of the ammunition during its impact on the target.

The front part 101 of the ammunition, as shown in the diagram of Figure 5, may include other elements. Indeed, in this figure 5, we find all the elements described in Figure 4 and constituting the ammunition. However a additional element has been added to the front of the game before 101. This element constituting a ballast 107 is placed, by example, in the warhead 104 and on part of the front part 101. This ballast 107 made of a dense material for example the tungsten allows, on the one hand, to improve the power of penetration of the front part 101 by increasing its mass, and, on the other hand, to reposition the center of gravity of the ammunition by moving it forward so as to reduce risk of rotation and bending of the ammunition when impact on the target.

The maximum diameter of the front part 101 has a value lower than that of the rear part 102 so that the front part 101 extends inside the rear part 102. In this way the rear part 102 covers a part of the front part 101 annularly. On the other hand, the effect penetration of the ammunition, in particular of the front part 101, being due mainly to kinetic energy it is essential to transmit the pushing force of the part rear 102 to the front part 101 during the first part of penetration. For this, the rear structure of the envelope 103 of the front part 101 presents, for example, a narrowing of conical type 108 on its periphery so that a fixing means, for example a fixing asymmetrical, for example a fixing ring 110 fixed to the rear part 102, for example, by laser welding after setting propellant loading place at a stop 113 of the fixing ring or by thread at the same stop, comes to bear on an oblique element 109 of the narrowing 108. This asymmetrical fixing makes it possible, on the one hand, to transmit the thrust from the rear part 102 of the ammunition to the front part 101 of the ammunition before the impact of the ammunition on the target, and, on the other hand to release, to the impact of the ammunition on the target, the front part 101 of the rear part 102 to facilitate penetration of the front part 101 of the ammunition in the target. This fixing ring 110, including a mode of embodiment is shown in detail in the figure 6, allows the front part 101 to be secured to the part rear 102 thanks to screws 111 positioned, for example, in holes 112, for example six in number, made in the ring 110. During the screwing, the screws 111 penetrate to the inside of the envelope 103 on a much smaller thickness to the thickness of the envelope 103 to avoid any disturbance leading to a deterioration of the front part 101. These screws 111 are, for example, shear screws which, when the ammunition penetrates the target, are sheared, allowing the front part to slide freely 101.

Given the dimensions imposed on the munition, dimensions of a front part 101 containing an amount of explosive charge required for maximum degradation of the target and a rear part 102 containing numerous modules allowing the realization of the different phases of operation (propulsion, guidance, steering, braking, tilt ...) the size of the ammunition must be limited by a particular arrangement of all the modules contained in the rear part 102 of the ammunition, each of modules fulfilling a function essential to efficiency desired ammunition.

• le séquenceur 114 est positionné annulairement sur une portion de l'arrière de la partie avant 101 ; ce séquenceur 114 a par exemple un diamètre inférieur au diamètre d'une enveloppe 115 du propulseur 116 de manière à ce que l'enveloppe 115 recouvre le séquenceur 114 lors de la réalisation de la munition. En effet, pour éviter tout désalignement des différents modules rendant la fabrication des munitions difficile et pour résoudre tout problème d'étanchéité et d'aérodynamisme, les modules de la partie arrière 102 susceptibles d'être positionnés autour de l'arrière de la partie avant 101 auront un diamètre inférieur au diamètre de l'enveloppe 115 afin d'être recouverts ;
• le propulseur 116 comportant par exemple un complément annulaire 117 est placé derrière le séquenceur 114. Une extrémité avant 118 de l'enveloppe 115 du propulseur 116 est fixée sur la butée 113 de l'anneau de fixation 110 maintenant l'ensemble à la partie avant. L'arrière du propulseur 116 comporte une tuyère 122 par lequel s'éjectent des gaz issus de la combustion, par exemple, d'un propergol solide ;
• l'empennage 120 constitué, par exemple, d'ailettes 121 est fixé, par exemple, sur le pourtour de la tuyère 122 du propulseur 116. Les deux ailettes représentées sur la figure 4 sont déployées et verrouillées, mais leur nombre n'est nullement limitatif. En position initiale, ces ailettes 121 sont repliées le long de la structure de l'enveloppe 115 ;
• le système de freinage 119 comportant, par exemple, un caisson 123 à l'intérieur duquel est placé un parachute 124, est placé en regard de la tuyère 122 ; il est fixé à la tuyère 122, par exemple, par un système de fixation déverrouillable dont un exemple de réalisation est représenté à la figure 7.

The rear part 102 comprises, for example, a braking system 119 inside which is placed a parachute 124, a tail 120 to ensure the balance of the ammunition, a thruster 116 to increase the speed of the ammunition, the triggering of which causes the release of the braking system 119, and a sequencer 114 to ensure the operation of the different phases. The modules of the rear part 102 are arranged as follows:

• the sequencer 114 is positioned annularly on a portion of the rear of the front part 101; this sequencer 114 has for example a diameter less than the diameter of an envelope 115 of the propellant 116 so that the envelope 115 covers the sequencer 114 during the production of the ammunition. Indeed, to avoid any misalignment of the different modules making the manufacture of ammunition difficult and to solve any problem of tightness and aerodynamics, the modules of the rear part 102 capable of being positioned around the rear of the front part 101 will have a diameter less than the diameter of the envelope 115 in order to be covered;
• the thruster 116 comprising for example an annular complement 117 is placed behind the sequencer 114. A front end 118 of the casing 115 of the thruster 116 is fixed to the stop 113 of the fixing ring 110 holding the assembly to the front part . The rear of the propellant 116 has a nozzle 122 through which gases from the combustion, for example, of a solid propellant are ejected;
• the tail 120 consisting, for example, of fins 121 is fixed, for example, on the periphery of the nozzle 122 of the thruster 116. The two fins shown in FIG. 4 are deployed and locked, but their number is by no means limiting. In the initial position, these fins 121 are folded along the structure of the envelope 115;
• the braking system 119 comprising, for example, a box 123 inside which a parachute 124 is placed, is placed opposite the nozzle 122; it is fixed to the nozzle 122, for example, by an unlockable fixing system, an exemplary embodiment of which is shown in FIG. 7.

• des premiers moyens mécaniques constitués d'un opercule 139 sur lequel est fixée au moins un doigt 138 ;
• des seconds moyens mécaniques composés d'une bille 135 et d'un élément 134 ;
• des troisièmes moyens mécaniques comprenant au moins un tirant 126 formé d'une embase 145 et d'une tige 128 ;

et dont la position sera décrite ultérieurement. Le système de freinage 119 contient le parachute 124 non représenté dont les suspentes 125 sont reliées à un ou plusieurs tirants 126, par exemple, positionnés à la périphérie interne du système de freinage 119 ; le ou les tirants 126 sont composés, par exemple, d'une embase 145 et d'une tige 128 de manière à ce que, d'une part, la tige 128 traverse l'avant 129 du système de freinage 119 par l'intermédiaire, par exemple, d'un premier trou cylindrique 130 positionné à la périphérie interne du système de freinage 119 et, d'autre part l'embase 145 repose sur l'avant 129 du système de freinage 119. En regard de ce trou cylindrique 130, un deuxième trou cylindrique 131 a, par exemple, été usiné sur l'arrière 132 du propulseur 116 de manière à ce que le tirant 126 assure la fixation du système de freinage 119 sur le divergent 122 du propulseur 116 par un écrou 133 positionné sur l'extrémité filetée de la tige 128 ; cet écrou 133 prend appui par exemple sur un élément 134 par exemple solide, placé à l'intérieur du deuxième trou 131 dont le diamètre est différent du diamètre du premier trou 130. Selon une variante, l'ensemble 131, 133 et 134 est monobloc et est vissé dans l'embase 145 grâce à la tige filetée 128. L'élément 134 est maintenu immobile dans l'arrière 132 du propulseur 116 par exemple, par une bille 135 reposant, par exemple, à l'intérieur d'une gorge 136 réalisée à la périphérie de l'élément 134 ; cette bille 135 placée, par exemple, dans un troisième trou cylindrique 137 perpendiculaire à un axe longitudinal X'X de la munition, est maintenue plaquée contre l'élément 134, par exemple par un doigt 138 placé dans un quatrième trou cylindrique parallèle à l'axe longitudinal XX' de la munition. Ce doigt 138 est un élément d'un opercule 139 par exemple circulaire, qui assure la fermeture du divergent 122 de l'arrière 132 du propulseur 116 ; cet opercule 139 est maintenu sur l'arrière 132 du propulseur 116, par exemple, par quatre doigts 138 et également par des vis à cisailler 140, par exemple au nombre de deux dont une seule est représentée sur cette figure. Il est possible d'utiliser d'autres systèmes de fixation que les vis à cisailler 140, par exemple des clips ou tout autre moyen. Cet opercule 139 ainsi fixé sur l'arrière 132 du propulseur 116 et solidaire des doigts 138 interdisant l'échappement des billes 135 maintenant les tirants 126 sur lesquels sont fixées les suspentes 125 du parachute 124, est désolidarisé, à un moment déterminé, sous l'action d'une force de poussée qui lui permet d'effectuer un mouvement de translation cisaillant d'une part les vis 140 et entraínant les doigts 138 fixés à cette dernière qui libèrent les billes 135 déverrouillant les éléments solides 134 et assurant ainsi un mouvement de translation selon l'axe X'X des tirants 126 qui, une fois libérés, permettent la désolidarisation ou séparation des deux modules constitués d'un propulseur 116 et d'un système de freinage.This system has different mechanical means:

• first mechanical means consisting of a cover 139 on which is fixed at least one finger 138;
• second mechanical means composed of a ball 135 and an element 134;
• third mechanical means comprising at least one tie 126 formed by a base 145 and a rod 128;

and whose position will be described later. The braking system 119 contains the parachute 124 not shown, the lines 125 of which are connected to one or more tie rods 126, for example, positioned at the internal periphery of the braking system 119; the tie rod (s) 126 are composed, for example, of a base 145 and a rod 128 so that, on the one hand, the rod 128 passes through the front 129 of the braking system 119 via , for example, a first cylindrical hole 130 positioned at the internal periphery of the braking system 119 and, on the other hand the base 145 rests on the front 129 of the braking system 119. Opposite this cylindrical hole 130 , a second cylindrical hole 131 has, for example, been machined on the rear 132 of the thruster 116 so that the tie rod 126 ensures the fixing of the braking system 119 on the divergent 122 of the thruster 116 by a nut 133 positioned on the threaded end of the rod 128; this nut 133 is supported for example on an element 134 for example solid, placed inside the second hole 131 whose diameter is different from the diameter of the first hole 130. According to a variant, the assembly 131, 133 and 134 is in one piece and is screwed into the base 145 thanks to the threaded rod 128. The element 134 is held stationary in the rear 132 of the thruster 116 for example, by a ball 135 resting, for example, inside a groove 136 produced on the periphery of element 134; this ball 135 placed, for example, in a third cylindrical hole 137 perpendicular to a longitudinal axis X'X of the munition, is held pressed against the element 134, for example by a finger 138 placed in a fourth cylindrical hole parallel to the 'longitudinal axis XX' of the ammunition. This finger 138 is an element of a cover 139 for example circular, which ensures the closure of the divergent 122 of the rear 132 of the thruster 116; this cover 139 is held on the rear 132 of the thruster 116, for example, by four fingers 138 and also by shear screws 140, for example two in number, only one of which is shown in this figure. It is possible to use other fixing systems than the shear screws 140, for example clips or any other means. This cover 139 thus fixed on the rear 132 of the thruster 116 and secured to the fingers 138 preventing the escape of the balls 135 holding the tie rods 126 on which the lines 125 of the parachute 124 are fixed, is disconnected, at a determined moment, under the action of a pushing force which allows it to carry out a translational movement shearing on the one hand the screws 140 and causing the fingers 138 fixed to the latter which release the balls 135 unlocking the solid elements 134 and thus ensuring a movement of translation along the axis X'X of the tie rods 126 which, once released, allow the separation or separation of the two modules consisting of a thruster 116 and a braking system.

The translational movement of the cover 139 is produced, for example, along an axis substantially parallel to X'X.

The pushing force separating the cover 139 is generated, for example, by gases from, for example, thruster 116 when it is on. The use of this thruster 116 to give the necessary thrust force simplifies the unlockable fixing system by using elements specific to the ammunition, in this case propellant gases 116 having the initial function of giving to the ammunition a determined speed to increase its efficiency, to trigger the separation of the elements.

The casing 123 of the braking system 119 has, for example, a square section to increase the available volume of the parachute necessary to obtain an incidence sufficiently low ammunition; in the example of realization, the incidence is around 30 °. To decrease this incidence, it would be necessary to increase the dimensions of the volume parachute which seems difficult considering the dimensions imposed for ammunition. The square section of the box 123 also facilitates the storage of ammunition inside the holds of an aerial vehicle which can be for example a cargo ship stand-off carrying ammunition as shown in the figure 8.

This air vehicle 141 carries numerous ammunition A, B, C comprising the various modules described previously. Ammunition A includes in its rear part the box 123 of square section containing the braking parachute not shown, the propellant whose casing 115 has by example a circular section and the tail unit comprising by example four fins 121 which, in the folded position, are housed in the space between the envelope 115 and the section prism square of box 123 and in its front part, the front part whose casing 103 is cylindrical.

The operation of the munition according to the invention, illustrated in FIG. 9, in an application intended for the deterioration of a horizontal target is as follows: ammunition is dropped, for example, from an air vehicle onto a concrete track on ground 142 of thickness E and which must be deteriorated. This ammunition includes the braking system 119 to the interior of which is placed the parachute, not shown, the empennage 120 to ensure the balance of the ammunition. The release of the thruster 116 allows the release of the system braking 119 and the front part 101 extending into the propellant 116 and containing the explosive charge necessary for the deterioration of the target and not shown in this figure 9. After a free fall flight time, represented by phase I and where the ammunition is subjected to terrestrial gravitation, to the resistance of the air and the speed acquired during ejection, the ammunition braking parachute is deployed, in phase II, to bend the trajectory of the ammunition towards the target, in this case the concrete track 142. At the end of the braking, the braking system is disconnected from the ammunition following phase III through the unlockable fixing under the action of gases from the propellant 116 which, on the other hand, make it possible to give, to the ammunition, a speed necessary for the penetration of the part before 101 in the concrete runway 142. In phase IV, during the impact of the front part 101 on the concrete track, the ring fixing not shown now the front part 101 to rest of the ammunition is detached allowing to penetrate only the front part 101 of the ammunition in the runway concrete, taking advantage of all the kinetic energy of the ammunition.

• de la résistance de la cible pénétrée,
• de la résistance du corps de la partie avant 101 contenant la charge explosive,
• de la quantité et de l'énergie spécifique de la charge explosive contenue dans la partie avant,
• de la position du "centre" de développement de l'explosion ; on définit une profondeur optimale "h" qui dépend de toutes les caractéristiques citées ci-dessus.

The destructive power of ammunition depends, in particular;

• resistance of the penetrated target,
• the resistance of the body of the front part 101 containing the explosive charge,
• the quantity and specific energy of the explosive charge contained in the front part,
• the position of the "center" of development of the explosion; an optimal depth "h" is defined which depends on all the characteristics mentioned above.

The perforating power must be defined so that the depth of penetration of the "center" of the explosion (in general the point of initiation of the explosive charge) or actually at the "h" position. For this purpose, it can be useful extend the priming channel, if necessary until near the warhead, i.e. immediately behind the ballast.

In the embodiment described, only one sequencer and part of the propellant are arranged so annular around the front part 101; this embodiment is particular and it is possible to place other modules necessary for the operation of ammunition around the front part 101 of the ammunition to respect the dimensions imposed on ammunition.

The arrangement of the modules in the ammunition according to the invention is particularly applicable to ammunition anti-tracks but can be used on any ammunition in front meet cost, transport and employment constraints and designed to punch a target with a high surface mechanical resistance before damaging it by explosion.

Figure 10 shows schematically another embodiment of the ammunition according to the invention.

This munition essentially comprises two parts: a front body C _A intended to perforate the material, for example concrete, forming the target, preferably penetrating it over its entire length, and a rear body C which may or may not be of greater diameter to that of the front body as shown in the figure. The rear body C comprises the various mechanical, electronic or pyrotechnic organs necessary for propelling, guiding, piloting or braking the ammunition; for this purpose it carries, for example, as shown in the figure, fins A forming a tail and a propulsion nozzle T.

The front body C _A is, in this embodiment, of substantially cylindrical shape and it is terminated at the front by a warhead O _G , substantially conical.

FIG. 11 represents a cross-sectional view, taken along an axis AA in the cylindrical part of the front body C _A.

The body C _A is constituted by an EN envelope of material having good mechanical resistance (steel, for example), enclosing an explosive charge C _H. The outer surface of the envelope EN, in its cylindrical part, has longitudinal grooves C _N , preferably over its entire length. The grooves C _N are shown in FIG. 12 as being of rectangular section but they can have other shapes, such as square, semi-circular, triangular, etc.

The operation of the ammunition according to the invention is the following.

The kinetic energy imparted to the ammunition is such that it allows it to perforate the target concrete mass, typically an aerodrome runway, by sinking, preferably over the entire length of the body before C _A. This perforation can in practice be a complete perforation of the thickness of concrete or, only, a semi-perforation. When carried out, a priming rocket not shown, for example contained in the rear body C, triggers the explosion of the charge C _H. The splines C _N produced in the front body C _A have the effect in particular, on the one hand, of reducing the frictional forces during the penetration of the body C _A into the concrete and, on the other hand, of increasing the stiffness transverse of the ammunition during the impact on the concrete, in order to reduce the risks of bending of the body before the engagement of the warhead.

In addition, in an alternative embodiment, the parameters (dimensions, material) of the casing and of the grooves are chosen so that each of the grooves functions as a longitudinal hollow charge when the charge C _H explodes, making thus a pre-fracturing of the concrete mass surrounding the body C _A ; this allows the improvement of the mucking power of the quantity of explosive charge contained in the ammunition and, consequently, the enlargement of the crater thus formed.

FIG. 12 represents a fractional cross-sectional view of an alternative embodiment of the grooved casing (EN) of the front body (C _A ) of the munition according to the invention.

In this figure, we find the envelope EN containing the explosive charge C _H , the outer surface of which has grooves C _N.

According to this variant, the inner surface of the envelope EN also has longitudinal grooves, marked C _I , alternated with the grooves C _N. The dimensions of these grooves C _I are chosen to favor the hollow charge effect mentioned above.

According to another alternative embodiment (not shown) of the grooves, these extend over all or part of the warhead O _G.

Figure 13 shows a diagram similar to that of Figure 10, on which are illustrated different variants of the munition according to the invention.

In this figure, we find the ammunition formed by the front body (C _A ) ending in the warhead O _G , and the rear body C carrying fins A and nozzle T. The front body C _A is formed by the envelope EN ' having splines C _N and containing an explosive charge C _H.

According to a first alternative embodiment, the grooved front body C _A , which is recalled that it is intended to perforate the target concrete over its entire length, extends inside the rear body C, which thus covers it annularly. The attachment of the rear body C to the front body C _A is then such that the body C is not significantly opposed to the penetration of the front body (C _A ) into the target concrete. This variant has the advantage of increasing the length of the front body C _A , for a given total length of ammunition, thereby notably increasing the amount of explosive charge C _H or, conversely, of reducing the total length of the ammunition to length of body C _A given: in fact, the annular space between the bodies C _A and C can be used to arrange at least some of the elements which are contained in the body C.

According to another alternative embodiment, the rocket for initiating the load C _H , marked F, is placed in the front body C _A , behind the load C _H.

According to another alternative embodiment, the front part of the body C _A , namely the warhead O _G and possibly a part of the cylindrical portion of the body C _A , is no longer filled with an explosive charge but with a dense material L , constituting a ballast. This material consists for example of tungsten. The presence of this ballast has the function, on the one hand, of improving the power of penetration of the body C _A by increasing its mass, at given section, and, on the other hand, of displacing the center of gravity ammunition forward, which reduces the risk of tilting, bending and ricochet of the munition at the time of engagement of the warhead.

Claims (25)

1. Munition launched from an aerial vehicle with a horizontal velocity and a horizontal attitude and intended to attack a target moving horizontally, the said munition comprising a braking system positioned at the tail of the munition, the said braking system being equipped with a parachute (11) which, when deployed, gives the munition trajectory a first curvature which is as close as possible to the vertical, the munition also comprising a retropropulsion means (13) positioned on the munition in such a way as to reduce the first curvature of the munition trajectory which was obtained using the parachute, which retropropulsion means is ignited after the parachute has been deployed, to increase the effectiveness of the said munition by reducing its obliqueness, the retropropulsion means being stopped at the end of the braking phase, and a retropropulsion means (116) then being set into operation to increase the velocity of the munition and thus penetrate the target.
2. Munition according to Claim 1, characterized in that the retropropulsion means is a retromotor (13) securely joined to a part of the munition.
3. Munition according to Claim 2, characterized in that the retromotor (13) is positioned as an annulus around a front part (1) of the munition.
4. Munition according to Claim 2, characterized in that the retromotor (13) has nozzles (14) positioned symmetrically with respect to a longitudinal axis XX' of the munition and providing thrust parallel to this axis XX'.
5. Munition according to Claim 1, characterized in that the braking system comprises a square-sectioned box structure (10) to contain the parachute (11) that gives the munition its first incidence.
6. Munition according to Claim 1, characterized in that the braking system is connected to a nozzle (9) of a motor (7) of the munition by an unlatchable fastening system (12).
7. Munition according to Claim 3, characterized in that the front part (1) is covered at least partially in an annulus by the rear part (2).
8. Munition according to one of Claims 1 to 7, comprising a front part (101), formed by a casing (103) containing an explosive charge (106) and a rear part (102) fixed to the front part (101) by a fastening means (110) and comprising a set of modules that allow the munition to operate, characterized in that at least one of the modules is placed in an annulus around part of the front part (101) of the munition in order to limit the bulk of the munition ensuring its effectiveness.
9. Munition according to Claim 8, characterized in that the modules of the rear part (102) which are placed in annulus around the front part (101) are a sequencer (114) and an additional part (117) of a motor (116).
10. Munition according to Claim 8, characterized in that the means of fastening the rear part (102) to the front part (101) is an asymmetric fastening means allowing the front and rear parts (101 and 102) of the munition to be held together before impact with the target and the front part (101) to be released from the rear part (102) after impact.
11. Munition according to Claim 8, characterized in that the means for fastening the rear part (102) to a front part (101) is a fastening ring (110) fastened, on the one hand, to the front part (101) by shear screws (111) and, on the other hand, to the rear part (102) by laser welding.
12. Munition according to Claim 8, characterized in that the front part (101) contains ballast (107).
13. Munition according to Claim 12, characterized in that the ballast (107) consists of dense material.
14. Perforating munition according to Claim 9, characterized in that the modules of the set of modules in the rear part (102) comprise a braking system positioned facing the motor (116) by means of an unlatchable fastening system and a tail unit fixed around the periphery of a divergent nozzle (122) of the motor (116).
15. Munition according to Claim 14, characterized in that the braking system consisting of a parachute (124) has a square-sectioned box structure (123) to increase the volume of the parachute (124).
16. Munition according to Claim 8, characterized in that the front part has a priming fuze (105) placed at the rear of the front part and extended by a priming channel (150) to shift the centre of explosion, thus increasing the effectiveness of the munition.
17. Munition according to Claim 8, characterized in that the diameter of the front part is smaller than the diameter of the rear part so that the front part penetrates inside the rear part over a given length.
18. Munition according to one of the preceding claims, characterized in that it comprises a front part (C_A) or body intended to penetrate the target, the front body comprising a casing (E) and an explosive charge (C_H) inside the casing, the outer surface of the casing having longitudinal grooves (C_N), and in that the material of the casing (E), its geometry and the geometry of the grooves (C_N) are such that the grooves form longitudinal hollow charges.
19. Munition according to one of the preceding claims, characterized in that the front body ends in a more or less conical ogive (O_G).
20. Munition according to Claim 19, characterized in that the grooves (C_N) are extended along the ogive (O_G).
21. Munition according to one of the preceding claims, characterized in that the internal surface of the casing (E) has longitudinal grooves (C_I) that alternate with the grooves (C_N) of the external surface.
22. Munition according to one of the preceding claims, characterized in that the ogive (O_G) and/or the front body (C_A) contains a dense material (L) forming ballast.
23. Munition according to one of the preceding claims, characterized in that the front body (C_A) is more or less cylindrical.
24. Munition according to one of the preceding claims, characterized in that it comprises a rear part or body (C) comprising the means for propelling, guiding, controlling or braking the munition.
25. Munition according to Claim 24, characterized in that the front body (C_A) is covered at least partially in an annulus by the rear body (C).

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