FR2830931A1 - EXPLOSIVE AMMUNITION - Google Patents

Abstract

Munition (1) comprises an explosive charge (2) inside a casing (3) around its axis (4), divided into two or more sectors (3a, 3b), one of which is designed to create fragments when a detonator (7) adjacent to the opposite sector is set off. <??>Preferred Features: The casing is made from at least two adjoining shells (8a, 8b), one covering an angle of 180 degrees or less, and made from a material such as steel or tungsten that breaks into fragments, and the other of a different material, such as a plastic or composite material or aluminum.

Description

Also in space.

  The technical field of the invention is that of explosive ordnance. These munitions include an explosive charge placed in an envelope surrounding an axis of the munition. Known ammunition known as formed charge which comprises

  a coating deformable by the shock wave of the explosive.

  Such ammunition provides, depending on the geometry of the

  coating, a jet of hollow charge or a forged core.

  We also know ammunition generating shards. These munitions include a pre-fragmented envelope which projects a burst of shards during initiation. The spatial distribution of the sheaf of shrapnel is generally

  360 around the axis of the ammunition.

  It is known to provide several initiators distributed around the envelope of such ammunition to allow a preferential focusing of the fragments according to one or more

  directions. The patent US5544589 describes such ammunition.

  However, these known munitions present in certain

case of disadvantages.

  Indeed, we are led today to ensure close defense of vehicles to project munitions in the direction of detected threats such as missiles or

anti-tank rockets.

  This ammunition ensures the destruction of the threat by the projection of fragments. However, this protection is provided at a reduced distance from the vehicle to be protected (of the order of 5 m). The fragments are therefore not only projected towards the threat but also towards the vehicle to be protected

  or support elements surrounding this one.

  Focusing the fragments is not enough to avoid such a collateral effect since the envelope of the ammunition is pre-fragmented over 360 and therefore it projects the fragments into

  all the space surrounding the envelope.

  It is the aim of the invention to propose an ammunition

  allowing to overcome such drawbacks.

  Thus the munition according to the invention makes it possible to more effectively control the distribution of the fragments towards the threat to be destroyed. It thus avoids the effects

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  collateral liable to damage the vehicle to be protected

  or injure the troops accompanying him.

  The invention also provides ammunition with modular operation, the terminal effect of which can be programmed before firing or else on trajectory as a function of

characteristics of the threat.

  The ammunition according to the invention also makes it possible to optimize the mass of explosive carried. The result is a lighter ammunition whose terminal efficiency is

  equivalent to that of known ammunition.

  Thus, the subject of the invention is an explosive ordnance comprising an explosive charge placed in an envelope surrounding an axis of the ammunition as well as at least one first initiator for this charge, ammunition characterized in that the envelope comprises at least two sectors, a first sector comprising means ensuring the formation of splinters when a first initiator which is disposed in the vicinity of a second sector is initiated, this second sector being

  devoid of means ensuring the formation of splinters.

  The first sector may preferably cover an angle

  less than or equal to 180 around an axis of the munition.

  According to one embodiment, the envelope may comprise a case formed of at least two contiguous shells in contact with the explosive charge, the first sector consisting of a first of the two shells which is made of a first material intended to generate flakes, the second sector being constituted by a second of the two shells which is made of a second material

  different in nature from that of the first material.

  The first material may have a density greater than or equal to 7 while the second material will have a density

less than or equal to 3.

  The first material can thus be made of steel or tungsten and the second material can be chosen from the following materials: plastic,

composite materials, aluminum.

  The means of initiation may include at least one

second initiator.

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  According to one embodiment, the second initiator may be placed in the vicinity of the first shell, the initiation of this second initiator ensuring the explosion.

  loading with a blast effect.

  According to another embodiment, the ammunition may include a concave coating disposed at a first end of the envelope and applied to the explosive charge, the second initiator being disposed at the

  near a second end of the envelope.

  According to another embodiment, the ammunition may include at least three initiators, one disposed in the vicinity of the first shell, another disposed in the vicinity of the two shell and another disposed in the

  near one end of the envelope.

  The initiators will be connected to a control means

  allowing the choice of one or other of the initiators.

  Other advantages of the invention will become apparent on

  reading of the description which will follow in different modes

  of realization, description made with reference to the drawings

  appended and in which: - Figure 1 shows in longitudinal section an ammunition according to a first embodiment of the invention, - Figure 2 is a cross section of the previous one along the plane whose trace AA is identified in Figure 1, - Figure 3 shows in longitudinal section an ammunition according to a second embodiment of the invention, - Figure 4 is a cross section of the previous one along the plane whose trace BB is identified in Figure 3, - Figure 5 is a cross section of an ammunition according to an alternative embodiment of the invention, - Figure 6 is a cross section of an ammunition according to another variant of the invention, - Figure 7 is a longitudinal section of an ammunition according to a third embodiment of the invention, - the figure is a cross section of this munition along the plane whose CC trace is marked in Figure 7, Figure 9 is a longitudinal section of a munition according a fourth embodiment of the invention, - Figure 10 is a cross section of this ammunition along the plane whose trace DD is identified in Figure 9. Referring to Figures 1 and 2, an explosive munition 1 according to a first embodiment of the invention, comprises an explosive charge 2 placed in

  an envelope 3 surrounding an axis 4 of the ammunition.

  The envelope 3 is here globally cylindrical with axis 4.

  The ammunition 1 shown here also includes a propellant 5 which is not shown in detail and which conventionally comprises a propellant charge 6 in the form of a block arranged in a chamber extended by a nozzle (not shown). This propellant is not the subject of the present invention and it is possible to define a

  ammunition according to the invention devoid of propellant.

  The ammunition is finally endowed with a tail (not

  shown) intended to ensure its stabilization in roll.

  The ammunition comprises at least a first initiator 7 which makes it possible to detonate the explosive charge 2. This first initiator 7 is disposed at the level of a generator of the envelope 3. In a conventional manner it is connected to a safety device and armament (not shown) which

  may be integral with the envelope of the ammunition.

  According to an essential characteristic of the invention, the casing 3 comprises at least two sectors: - a first sector 3a comprising means ensuring the formation of splinters when the first initiator 7 is initiated, and - a second sector 3b devoid of means ensuring the

splinter formation.

  The first initiator 7 is arranged in the vicinity of the second sector 3b of the envelope. Thus the detonation wave initiated by the initiator 7 will progress in the explosive charge 2 in a substantially radial direction towards the first sector 3a, thus ensuring

  optimum speed for projecting shards.

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  According to this first embodiment, the envelope 3 comprises a case formed by two shells 8a and 8b which are contiguous and which surround the explosive charge 2. According to the variant shown in Figures 1 and 2, the two shells 8a and 8b are semi-cylindrical . Each sector 3a, 3b covers

  therefore an angle of 180 around the axis 4 of the ammunition.

  The two shells 8a and 8b are arranged in a tube 9 which will be made of a light material, for example in

  aluminum, plastic or composite.

  The first sector 3a is constituted by the first shell 8a. This first shell is made in one

  first material intended to generate splinters.

  We can for example make this first shell 8a

  made of steel or dense material (for example tungsten).

  The first material may be weakened to ensure preforming of the chips. The embrittlement could in a conventional manner be obtained by mechanically producing grooves forming a network having as mesh the dimension desired for the splinters. We can also achieve embrittlement by electronic bombardment or treatment

  thermal localized along such a network.

  We can also ensure a modulation of the shock wave to which the first shell is subjected according to the desired network by providing inserts or areas devoid of explosive between the explosive and the first shell (for example a grid or else grooves

laid out in the explosive).

  These solutions are well known to those skilled in the art and

  will not be described in more detail.

  One could also provide inserts (metal or plastic grid) disposed between the first shell and the tube 9 or else embedded in the material

of tube 9.

  The second sector 3b is constituted by the second shell 8b which is made of a second material which is

  different in nature from that of the first material.

  As the second material, a material will be chosen which generates little or no splinters during the initiation of the

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  charge. It will suffice to adapt a low density material (less than or equal to 3000 kg / m3) which will ensure the mechanical strength of the assembly but which will not generate during the

  operation only low vulnerability shards.

  We can thus make the second shell 8b in one

  plastic material for example a polyamide.

  The second shell could also be made of a composite material, such as a filament wound, or of aluminum. A radial pin 10 ensures axial positioning and

  angular of the two half-shells with respect to the tube 9.

  According to the embodiment which is represented here, the first initiator 7 is constituted by a tablet of an explosive composition, housed in a hole arranged in the explosive charge 2. This tablet is itself initiated by a detonator 11 which is connected by a wire 12 to a firing control device (not shown) secured to the launching system (not shown) or else secured to the munition itself. The detonator is applied in contact with the initiating tablet 7 through a radial orifice

  13 arranged in the second shell 8b.

  A closure cap 19 is screwed or glued to the tube 9 and it ensures the axial connection of the explosive charge

  and shells 8a and 8b relative to the tube 9.

  The assembly formed by the initiator 11, the explosive charge 2 and the first shell 8a constitutes a charge

generator of shards.

  The mounting of this ammunition is carried out in the following manner: An explosive block, for example of hexogen or octogen, is produced, inside which a radial hole is arranged.

  intended to receive the means of initiation.

  The initiation means 7 are placed inside this hole and then the explosive is placed inside the two shells 8a and 8b, ensuring that the initiator 7 is opposite the

shell hole 13 8b.

  The shells 8a, 8b fitted with the explosive charge are inserted inside the tube 9, taking care to orient

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  the load correctly angularly. The pin 10 is then placed and glued into the tube to ensure the axial connection of the load, the shells and the tube. The detonator 11 fitted with its wire 12 is placed in the

  tube 9 and opposite the initiator 7.

  The ammunition thus described operates in the following manner. The initiator 7 is triggered on the trajectory of the munition by a control order transmitted by the wire 12. The explosive charge 2 is then detonated. The detonation wave progresses substantially radially from the second shell 8b to the first shell 8a. This is fragmented in the form of shards which are projected at a

speed of the order of 1800 m / s.

  The second shell being made of a light material which does not generate splinters or slightly vulgar splinters, we are sure to obtain an effective spray in a well-defined sector which is delimited as much as possible by the directions dl and

d2 visible in Figure 2.

  This avoids collateral effects.

  To simplify the drawings, a military head has been described here, the triggering of which was caused from the launching system using a wire. In order to ensure that the fragments are sent in the direction of the threat, it will be advantageous to equip the ammunition with a rocket (not shown) of radar or infrared technology and having a direction of detection parallel or close to the direction of effectiveness of the flash charge. This direction is the bisector of the angle formed by the lines dl and d2 (figure 2). The rocket will be connected to the initiator 7 and it will trigger the charge towards the threat it

will have detected.

  Different variants are possible without leaving the frame

of the invention.

  FIG. 5 thus shows in section a munition 1 which differs from that of FIG. 2 in that the explosive charge 2 does not completely fill the volume delimited by

shells 8a and 8b.

  Indeed, given the fact that only the shell 8a has a damaging effect, it is not necessary to completely fill the internal volume of the munition with explosive. The explosive charge will then be machined in the form of a "wedge" delimited by two planes 21a, and 21b and by the

first shell 8a.

  The initiator 11 will be placed at the top of the corner.

  Plans 21a and 21b can be applied on a

  sheet metal cover secured to the second shell 8b.

  They can more simply be kept wedged relative to the second shell 8b using filling blocks 20a, 20b made for example of foam.

synthetic.

  Such a variant makes it possible to lighten the ammunition without affecting its effectiveness. It also makes it possible to reduce rear effects, the timing 20a, 20b ensuring damping

  of the shock wave received by the second shell 8b.

  The volume occupied by the setting can also be used

  to house a security and arming device.

  It is also possible, as a variant, to produce a munition in which the first sector 3a covers an angle less than 180 around the axis 4 of the munition. Figure 6 thus shows in section a munition in which

  the angle covered by the first sector 3a is 120.

  It will be noted that the tube 9 has not been shown on the

Figures 5 and 6.

  Figures 3 and 4 show ammunition according to a

  second embodiment of the invention.

  This munition differs from that shown in Figures 1 and 2 in that it also includes a concave coating 14 which is applied to the explosive charge 2. This coating is disposed at a first end (or front end) of the envelope 3. It has a symmetry

  of revolution around axis 4 of the ammunition.

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  The periphery of the coating is housed in a groove which is arranged inside the shells 8a and 8b which

  thus ensure the axial securing of the coating.

  A stop ring 18 is fixed by screw to the tube 9. It ensures the axial immobilization of the shells and of the loading

relative to tube 9.

  A second initiator 15 produced in the form of a tablet of an explosive composition is placed in the vicinity of a second end of the envelope. He is housed in a

  axial hole in the explosive charge 2.

  This tablet 15 is itself initiated by a detonator 16

  which is connected by a wire 17 to the ignition device.

  The wires 12 and 17 can be grouped together in the form of a strand of four wires. It will also be possible to use detonators 11 and 16 each provided with a logic circuit incorporating a memory containing an address making it possible to recognize one or the other of the detonators by means of a communication protocol (technical

  communication standard by "BUS").

  In this case a single pair of wires will initiate

  either one of the two detonators 11 or 16.

  To facilitate mounting of the ammunition, the wire 17 is housed in a groove in the wall of the tube 9 and in

  a groove 24 arranged in the bottom 25 of the tube 9.

  The assembly formed by the second initiator 15, the explosive charge 2 and the coating 14 constitutes a charge generating the core. The initiation of the initiator causes a shock wave which progresses substantially axially in the explosive charge 2. This shock wave leads to the formation of a self-forged core by reversing the coating 14. The core is projected at a speed of

  around 2000 m / s along axis 4.

  This munition therefore has two different operating modes. If the first initiator 7 is triggered, the ammunition generates a burst of splinters with reduced rear and collateral effects thanks to the presence of the second

  shell 8b as well as the bottom 25 of the tube 9.

  o 2830931 If the second initiator 16 is triggered, the ammunition generates an axial cycle thanks to the coating 14. There is also in this case a projection of shards by the first shell 8a, but the speed of the shards is lower than for the ammunition of figure 1 taking into account the orientation

  substantially axial of the shock wave.

  The choice of one or the other of the initiators 7 or 16 is ensured by the firing control device integral with the launch system or the rocket of the

ammunition.

  This choice will be made according to the characteristics of the threat detected. The flash charge is effective against missiles whose envelope it destroys. The core-generating charge has piercing effectiveness against armored targets. It can be used to counter in direct attack a target such as a vehicle or a missile with

reinforced warhead.

  If the firing order is transmitted from a ground launch system, it is of course possible to ensure this transmission by radio or optical means. In this case the ammunition will include a special electronic fuse incorporating a command receiver

  from the launch system.

  The ammunition rocket may also be a programmable 2s rocket which will receive, at the launch system, a programming of the triggering instant as well as the desired operating mode. This programming can be carried out by contact or by induction. The fuse may then also include means for detecting

the threat.

  As a variant, the coating may be given different shapes making it possible to combine the formation of a core with that of splinters. To do this, it will suffice to provide embrittlement at an annular peripheral zone 3s of the covering, an axial zone ensuring the

nucleus formation.

  We can also produce a coating that does not generate

that shards.

  Figures 7 and 8 show ammunition according to a

  third embodiment of the invention.

  This mode differs from that according to FIG. 1 in that a second initiator 22 is arranged in the vicinity of the

s first shell 8a.

  This second initiator is connected by a wire 23 to the

  firing control device.

  As in the second embodiment (FIG. 3), a common strand of the wires 12 and 23 can be produced or else

  use a single ignition control bus.

  From the mounting point of view, the second initiator 22 is disposed in a radial hole made in the explosive block 2 and the wire 23 is housed in a machined longitudinal groove

on the explosive device 2.

  The wire 23 is therefore placed between the explosive 2 and the first shell 8a. Thus it is not necessary to machine the latter to ensure the mounting of the second initiator 22. There is therefore no loss of the annoying efficiency of

the first shell.

  The wire 23 is also housed in a groove 24 made

in the bottom 25 of the tube 9.

  Connectors 26a, 26b (shown diagrammatically in dotted lines) can be housed at the level of this groove for

  facilitate assembly of the ammunition.

  In fact, on the one hand, the explosive charge fitted with its two initiators 7 and 22 and a

  first part of the wire 23 equipped with a connector 26a.

  We will also carry out the assembly of the tube which will receive

  a second part of the wire 23 equipped with the connector 26b.

  We will then connect the connectors before introducing

the charge in the tube 9.

  It is also advantageously possible to provide a bottom 25 for the tube which is removable. This will facilitate the electrical connection after introduction of the load

explosive in tube 9.

  The ammunition according to this third embodiment also has two modes of operation:

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  The flash charge mode already described which is obtained

  when the first initiator 7 is triggered.

  A blast charge mode which is obtained when

  the second initiator is triggered.

  In fact, the second initiator 22 is disposed substantially at the level of the first shell 8a generating splinters. The shock wave it generates propagates in the load in a substantially radial direction and in

  direction of the second shell 8b.

  The chips generated by the first shell then have a reduced speed. The second shell is not designed to generate annoying splinters. The only major effect obtained with this ammunition is therefore a blast effect which is oriented radially in the direction of the second shell.

  8b and which is partially focused by the first shell 8a.

  This blast effect can be reinforced by using a

  explosive charge 2 incorporating aluminum powder.

  The blast effect operating mode is more particularly used to counter kinetic energy projectiles. The flashing mode of operation is

  used to counter missiles or rockets.

  Figures 9 and 10 finally show a munition according to a fourth embodiment i sat ion which differs from the previous ones.

  that the munition includes three initiators 7, 15 and 22.

  This munition therefore has three different operating modes: local flash charge, charge effect

  focused breath, core generation charge.

  The choice of one or the other of these operating modes will be determined by the control device (on the ground or integral with the ammunition) according to the threat and the appropriate firing order will then be triggered on the trajectory. .

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Claims (9)

RESELL I CAT IONS   1- Explosive ammunition (1) comprising an explosive charge (2) placed in an envelope (3) surrounding an axis (4) of the ammunition as well as at least one first initiator for this charge, ammunition characterized in that the envelope (3) comprises at least two sectors (3a, 3b), a first sector (3a) comprising means (8a) ensuring the formation of splinters when a first initiator (7) which is arranged in the vicinity of a second sector (8b) is initiated, this second sector being devoid of means ensuring the splinter formation.   2- Explosive ordnance according to claim 1, characterized in that the first sector (3a) covers an angle less than or equal to 180 around an axis (4) of the ammunition.   3- Explosive ordnance according to one of claims 1 or   2, characterized in that the envelope comprises a case formed of at least two shells (8a, 8b) contiguous and in contact with the explosive charge (2), the first sector (3a) being constituted by a first (8a) of the two shells which is made of a first material intended to generate splinters, the second sector (3b) being constituted by a second (8b) of the two shells which is made of a second material of a different nature from that of the first material.   4- Explosive ordnance according to claim 3, characterized in that the first material has a density greater than or equal to 7 and the second material has a density less than or equal to 3.   5- Explosive ammunition according to claim 4, characterized in that the first material is steel or tungsten and in that the second material is chosen from the following materials: plastic, materials composites, aluminum.   6- Explosive ordnance according to one of Claims 1 to 5,   characterized in that the initiation means include minus a second initiator (15). 4 2830931   7- Explosive ammunition according to claim 6, characterized in that the second initiator (15) is arranged in the vicinity of the first shell (8a), the initiation of this second initiator ensuring the explosion   S loading with a blast effect.   8- Explosive ammunition according to claim 6, characterized in that it comprises a concave coating (14) disposed at a first end of the envelope (3) and applied to the explosive charge (2), the second initiator (15) being arranged in the vicinity of a   second end of the envelope (3).   9- Explosive ammunition according to claims 7 and 8,   characterized in that it comprises at least three initiators (7,15,22), one (22) disposed in the vicinity of the first shell (8a), another (7) disposed in the vicinity of the second shell (8b) and another (15) arranged at   near one end of the envelope (3).   - Ammunition according to one of claims 6 to 9,   characterized in that the initiators (7,15,22) are connected to a control means allowing the choice of one or the other