EP2791616B1 - Munition, charge for such a munition, and method of manufacturing such a munition - Google Patents

Description

The present invention relates to a munition, in particular a bomb and more particularly an aerial bomb, of the type comprising an elongate body housing an explosive charge and an inert charge, and a firing device. The present invention also relates to a load adapted to such an ammunition and a method of manufacturing such an ammunition.

A munition of the aforementioned type is generally intended to be connected to a transport platform, including an aircraft. The moment of inertia, the aerodynamics and the volumes of such an ammunition are dimensioned to answer a precise specifications.

The integration of a munition on a transport platform being extremely complex and expensive, it is desirable that the improvements made to it modify at least its aerodynamic and ballistic characteristics as well as its architecture, compared to the usual ammunition.

Air weapons are now mainly used to accurately target ground targets such as bunkers, armored vehicles, etc.

When these targets are positioned in an urban environment, it is desirable to limit the possible collateral effects of ammunition, by directing the blast effect as well as the explosions generated by their detonation, towards the targeted targets.

One way to reduce these collateral effects is to reduce the total mass of explosive in the munition. In the past, ammunition has been developed in which an inert material replaces part of the explosive inside the ammunition. The inert material used generally has a density close to that of the explosive. The patent application WO 2008/118235 in particular, which forms a starting point for the preamble of claim 1, describes an aerial ammunition with reduced collateral effects in which the inner wall of the body is coated with an inert mass compensation material and the explosive charge occupies the remaining volume of the ammunition body, while being in contact with the firing device.

This configuration does not reduce the collateral effects of the ammunition satisfactorily. It also requires coating the inner wall of the body of the munition with the inert material, before introducing the explosive charge. The manufacturing process of this munition is therefore complex and expensive.

The person skilled in the art is therefore always in search of a munition, in particular an air munition, making it possible to effectively reduce the collateral effects, easy to manufacture, and nevertheless preserving the main architectural, mass and ballistic characteristics of the known munitions. .

The object of the present invention is to provide a new munition fulfilling these conditions.

This object is achieved by means of a munition of the aforementioned type, in which the inert charge is interposed between the firing device and the said explosive charge, and which further comprises at least one pyrotechnic transmission unit provided with an extension pyrotechnic, said pyrotechnic transmission unit coupling the explosive charge to the firing device, to allow the detonation of said explosive charge under the action of the firing device.

In the present application, the term "pyrotechnic transmission unit" is understood to mean any element capable of propagating a detonation initiated by the firing device to the explosive charge, even though the latter is positioned at a distance from said firing device.

Furthermore, by pyrotechnic extension means any element adapted to transmit a detonation wave, initially resulting from the firing device, without modifying said detonation wave, and in particular its surface amplitude, its intensity (or its power), or its form.

Generally, a pyrotechnic extender is an elongated member, that is to say longer than wide, rigid or flexible, of substantially constant section.

Preferably, the pyrotechnic extender comprises an explosive compound of homogeneous composition, identical or different from that of the explosive charge. More preferably, the pyrotechnic extender comprises a single explosive compound of homogeneous composition, especially monolithic. Even more preferably, the pyrotechnic transmission unit comprises a single explosive compound of homogeneous composition, preferably monolithic.

Preferably, the pyrotechnic extender has a maximum radial dimension substantially less than the maximum diameter the ammunition, preferably at least 5 times smaller than this diameter, and even more preferably at least 20 times smaller than this diameter.

The purpose of the present invention is, as indicated above, to provide a munition that effectively reduces collateral effects, without modifying the architectural, mass and ballistic characteristics of known ammunition. According to the invention, such an ammunition is obtained by reducing the volume of explosive charge contained in a munition of conventional configuration and positioning said explosive charge at the location of the most appropriate munition, in particular its front end, while retaining the firing device at the rear of the munition, the inert load being positioned between the explosive charge and the firing device.

As it comprises the same elements as a standard ammunition (explosive charge, inert load, firing device), which are simply arranged differently, the munition according to the invention has the same mass, the same center of gravity and the same moments of inertia as a standard ammunition, guaranteeing perfect interchangeability (possible connection to the same ports, compatibility with known kits and guidance logic, etc.).

The invention allows to "dose" at will, by construction, the power of the ammunition, for a standard size and interchangeable ammunition.

The objective being to limit the volume of explosive material inside the ammunition, it is understood that the pyrotechnic transmission unit will preferably have the smallest possible volume.

The pyrotechnic extender which forms the longest part of the pyrotechnic transmission unit, has, in particular, a volume and therefore a radial dimension or the most limited width possible.
Preferably, the pyrotechnic extender is longer than wide, and in particular at least 10 times longer than wide, preferably at least 20 times longer than wide.

According to an advantageous arrangement, the length of the pyrotechnic extender is at least equal to 1/2 times, preferably at least 2/3 times the total length of the munition.

As previously indicated, according to an advantageous aspect of the present invention, the firing device is disposed at the end rear of the ammunition, and the explosive charge is disposed at its front end.

In the present application, the term "front end" of the ammunition means that oriented in the direction of movement of said munition, and the rear end, its opposite end in the axial direction.

Due to the positioning of the explosive charge at the front of the munition, the blast effect and the fragments resulting from the detonation are directed in a privileged way forward, that is to say toward the target, and the collateral effects towards the rear of the ammunition are considerably reduced.

According to an advantageous exemplary embodiment, the pyrotechnic transmission unit further comprises a first ignition relay coupling said pyrotechnic extender to the explosive charge.

In the present application, the term "booster relay" means any priming device adapted to transmit a detonation wave by modifying the surface amplitude and / or the intensity and / or the shape of this detonation. wave.

For example, the priming relay may be used to increase the surface of the detonation wave transmitted to the explosive charge when the pyrotechnic extender has a diameter smaller than the critical diameter of the explosive charge (ie the diameter below which the detonation the charge can not take place). The priming relay will then have a flared shape in the direction of the explosive charge, its maximum diameter being greater than the critical diameter of said load.

An example of a priming relay is known from the Canadian patent application CA 2,066,139 . This application describes an ammunition comprising a low-sensitivity explosive charge, requiring the interposition of a priming relay between said explosive charge and the firing device in order, firstly, that the diameter of the wave transmitted to the explosive charge is greater than the critical diameter for detonation of said charge, and, secondly, that the power of the detonation wave is sufficiently large. To increase the diameter of the detonation wave, the ignition relay is provided with an annular wave generator comprising a conical cap. To increase the power of the detonation wave, the ignition relay further comprises a bi-explosive generator of known type.

In another example, the pyrotechnic transmission unit comprises a first priming relay coupled to the explosive charge, a second firing relay coupled to the firing device, and a pyrotechnic extender coupling said firing relays.

According to an advantageous arrangement of the invention, the pyrotechnic transmission unit is at least partially embedded in the inert load.

According to another advantageous arrangement, the explosive charge, the inert charge and the firing device are located, in this order, one after the other inside the body of the ammunition, in the direction axial axis of this body, the explosive charge being closest to the front of the munition.

According to an exemplary embodiment of the invention, the interface between the explosive charge and the inert load extends substantially perpendicular to the axis of the body. The explosive charge and the inert charge are therefore not superimposed in the radial direction. Preferably, the explosive charge extends substantially over a whole diameter of the body.

In the present application, it will be said that two elements are coupled when the detonation of one leads to the detonation of the second.

As indicated above, the coupling between the firing device and the explosive charge is achieved by means of the pyrotechnic transmission unit, which is coupled to each of them. The couplings between the pyrotechnic transmission unit and the firing device or the explosive charge may or may not be remote.

Thus, according to an exemplary embodiment, the pyrotechnic transmission unit and the explosive charge are connected to one another. In this case, the pyrotechnic transmission unit and the explosive charge can be connected to one another via an adhesive layer. Alternatively, it may simply be against a surface of the explosive charge. It can still be partially embedded in it.

According to another example, the pyrotechnic transmission unit is separated from the explosive charge by a layer of an inert material, in particular an inert material forming part of the inert filler. In general, the thickness of this layer must be dimensioned so that the detonation from the pyrotechnic transmission unit can propagate by influence to the explosive charge. Advantageously, the layer of inert material is a thin layer, typically less than or equal to 30 mm.

In another example, the explosive charge and the explosive compound contained in the pyrotechnic transmission unit form a monolithic assembly of homogeneous composition.

Advantageously, the munition comprises at least two pyrotechnic transmission units spaced apart from each other. More generally, the multiplication of the pyrotechnic transmission units makes it possible to make reliable the transfer of the initial detonation of the firing device which may, by construction, not be perfectly axisymmetric.

In one example, the pyrotechnic transmission unit comprises a rigid or flexible tube, rectilinear or not, containing an explosive compound. In particular, the pyrotechnic transmission unit may comprise a flexible detonating cord as described for example in the patent application. WO9104235 . The pyrotechnic transmission unit may also comprise a tube comprising a granular explosive charge (of the RDX or HMX type) or a compressed explosive (of the hexocire type) or a cross-linked binder composite explosive (of the HMX or RDX / polyurethane binder type) . The tube may be plastic or metal.

In another example, the pyrotechnic transmission unit comprises a rigid bead of any shape made of an explosive compound, said bead can be naked or covered with a linker. In particular, such a cord constitutes all or part of the pyrotechnic extender.

Advantageously, to allow efficient transmission of the detonation, the section of the pyrotechnic transmission unit increases at its end connected to the explosive charge. It is for example flared towards its end, or it has a tubular end portion of increased section.

The present invention also relates to a load adapted to be integrated into an ammunition as defined above, comprising an explosive charge and an inert charge, and further comprising at least one pyrotechnic transmission unit provided with a pyrotechnic extender, said unit pyrotechnic transmission being adapted to transmit to said explosive charge a detonation initiated remotely, on the side of the inert charge opposite said explosive charge.

According to an advantageous aspect, the pyrotechnic transmission unit, and in particular said pyrotechnic extender, is at least partly embedded in the inert charge.

According to an exemplary embodiment, the load further comprises a sheath adapted to receive the firing device for initiating the detonation, the inert load being interposed between the explosive charge and said sheath.

According to another example, the pyrotechnic transmission unit, and in particular said pyrotechnic extender, is connected to the explosive charge and / or to said sheath by contact.

According to another example, the pyrotechnic transmission unit is coupled to the explosive charge and / or to said sheath through a layer of inert material, in particular an inert material forming part of the inert filler.

1. a) on fournit un corps creux allongé comportant une ouverture d'introduction à l'une de ses extrémités,
2. b) on introduit dans le corps une charge explosive, une charge inerte et au moins une unité de transmission pyrotechnique munie d'une rallonge pyrotechnique, de sorte que l'unité de transmission pyrotechnique soit couplée à la charge explosive, et
3. c) on couple l'unité de transmission pyrotechnique à un dispositif de mise à feu,
   la charge inerte étant alors interposée entre le dispositif de mise à feu et ladite charge explosive, et l'unité de transmission pyrotechnique permettant la mise en détonation de ladite charge explosive sous l'action du dispositif de mise à feu.

The present invention also relates to a method for manufacturing a munition, comprising at least the following steps:

1. a) an elongate hollow body is provided with an opening opening at one of its ends,
2. b) introducing into the body an explosive charge, an inert charge and at least one pyrotechnic transmission unit provided with a pyrotechnic extender, so that the pyrotechnic transmission unit is coupled to the explosive charge, and
3. c) the pyrotechnic transmission unit is coupled to a firing device,
   the inert load then being interposed between the firing device and said explosive charge, and the pyrotechnic transmission unit for detonation of said explosive charge under the action of the firing device.

According to an example of implementation of the method, the explosive charge is introduced inside the body in a non-solidified state, then it is solidified therein.

For example, the explosive charge is introduced into the body in the form of a pasty explosive compound containing a crosslinkable binder and its crosslinking agent. In this case, the pasty explosive compound solidifies by crosslinking said binder.

In another example, the explosive charge is introduced inside the body in the form of a molten explosive compound. In this case, the explosive compound solidifies by lowering the temperature.

According to yet another example, the explosive charge is introduced inside the body in the form of a monolithic block of suitable geometry.

According to an example of implementation of the method, the inert filler is introduced into the body in a non-solidified state, then it is solidified therein.

In another example, the inert filler is inserted inside the body in the form of a monolithic block of suitable geometry.

According to an example of implementation of the method, in step b), the explosive charge is introduced into the body at first, the pyrotechnic transmission unit is introduced into the body and coupled with said explosive charge in a second time, and the inert charge is introduced into the body in a third time.

In this case, the inert charge is generally introduced into the body in a non-solidified state, so that it coats the pyrotechnic transmission unit, and in particular said pyrotechnic extender.

In one example, the pyrotechnic transmission unit is partially embedded in the explosive charge when it is still in the non-solidified state.

In one example, the pyrotechnic transmission unit is connected to the explosive charge by gluing. It can also be simply in contact with it, without being stuck.

According to another example of implementation, in step b), the explosive charge and the inert charge are introduced inside the body in a first step, then the pyrotechnic transmission unit is introduced into the body in a Secondly.

In this case also, the inert filler is generally introduced into the body in the pasty state. The pyrotechnic transmission unit is then immersed in the non-solidified mass of inert material until it is in the vicinity of or in contact with the explosive charge.

According to another example of implementation of the method, during step b), an empty tube is introduced and positioned inside of the body, so that its end reaches the volume provided for the explosive charge, is poured through said tube an explosive compound in the pasty state, to fill the volume provided for the explosive charge and the internal volume of the tube, solidifies the explosive compound, and then introduces the inert filler inside the body of the munition.

In one example, the tube is removed after solidification of the explosive. In this case, the bar of explosive molded in the tube constitutes all or part of the pyrotechnic transmission unit, and said bar of explosive forms in particular the pyrotechnic extender.

According to another example, the tube is kept inside the body after solidification, the tube filled with explosive compound constituting all or part of the pyrotechnic transmission unit, and said filled tube notably forms the pyrotechnic extender.

According to another example of implementation of the method, the explosive charge and the pyrotechnic transmission unit form a preformed assembly which is introduced inside the body.

According to one example, the explosive charge and the explosive compound contained in the pyrotechnic transmission unit form a monolithic assembly of homogeneous composition.

In one example, after having been introduced inside the body and before the introduction of the inert load, the pyrotechnic transmission unit is held in position by wedging means.

Several examples of embodiments are described in this presentation. However, unless otherwise specified, the features described in connection with any exemplary embodiment may be applied to another embodiment.

• la figure 1 est une vue en perspective, partiellement découpée, d'une munition selon un premier exemple de réalisation de la présente invention,
• la figure 2 est une vue en coupe longitudinale selon II-II de la figure 1, sur laquelle, pour des raisons de simplification, seuls certains éléments sont montrés en coupe,
• la figure 3 est une vue en coupe longitudinale selon III-III de la figure 1, sur laquelle, pour des raisons de simplification, seuls certains éléments sont montrés en coupe,
• les figures 4A à 4F illustrent différentes étapes successives d'un exemple de mise en oeuvre du procédé de fabrication d'une munition telle que représentée sur les figures 1 à 3,
• les figures 5 à 7 illustrent différentes variantes de couplage entre une unité de transmission pyrotechnique et la charge explosive,
• les figures 8 et 9 illustrent différentes variantes de couplage entre une unité de transmission pyrotechnique et le dispositif de mise à feu.

The invention will be better understood and its advantages will appear better on reading the detailed description which follows, examples of embodiments shown in a non-limiting manner. The description refers to the accompanying drawings in which:

• the figure 1 is a perspective view, partially cut away, of a munition according to a first embodiment of the present invention,
• the figure 2 is a longitudinal sectional view along II-II of the figure 1 , on which, for reasons of simplification, only certain elements are shown in section,
• the figure 3 is a longitudinal sectional view along III-III of the figure 1 , on which, for reasons of simplification, only certain elements are shown in section,
• the Figures 4A to 4F illustrate different successive steps of an exemplary implementation of the method of manufacturing an ammunition as shown in FIGS. Figures 1 to 3 ,
• the Figures 5 to 7 illustrate different variants of coupling between a pyrotechnic transmission unit and the explosive charge,
• the Figures 8 and 9 illustrate different coupling variants between a pyrotechnic transmission unit and the firing device.

On the figure 1 , there is shown a munition 10 according to a first embodiment of the present invention, comprising an elongate body 12 of axis AA 'formed of a first section 14 or ogival front section, tapering towards its front end 12a, and a second section 16 or rear section, slightly narrowed towards its rear end 12b. According to an alternative embodiment, the body 12 of ammunition could take any other elongated form.

The body 12 has, in the example, an opening 18 at its front end 12a, and an opening 19 at its rear end 12b.

Throughout the present application, it will be said that the front of the ammunition corresponds to its side directed in the direction of movement (ie in the direction of the target), and that the rear of the ammunition corresponds to its opposite side in the direction of axis A-A '.

As illustrated on the figure 2 , a firing device or detonator 20 is located in the vicinity of the rear end 12b of the body 12. In the example illustrated, more precisely, the firing device 20 is inserted inside a sheath receiving 21 provided at the rear end of the body 12 (hereinafter rear sheath).

At its front end 12a, the body 12 houses a functional element 22, in particular a ballistic control member such as a homing device for guiding the munition, a proximity detector for triggering the munition close to the target or a target. altimeter. In the example, this functional element 22 is disposed inside a front receiving sheath 23, which closes the aforementioned opening 18.

The functional element 22 and the firing device 20 are fed by a supply member 34 (shown in FIG. figure 2 ), located generally outside the body 12 of the munition, by means of electrical conduits 31, 32. In the example, the electrical conduits 31, 32 respectively extend from the functional element 22 and the switching device. fire 20 to a feed zone 30 located here in the vicinity of the middle of the body 12 in the axial direction A-A '. The supply zone 30 has an opening 33 to the outside of the body 12 through which the electrical conduits 31, 32 are connected to the supply member 34. The supply member 34 is for example a wind turbine, in particular a wind turbine mounted on the body 12 of the munition, outside thereof.

The munition further comprises two anchor wells 71, 72 formed in the body 12, and for its connection to a platform of carriage of the aircraft, the helicopter or the drone on which the ammunition is for example mounted. In the example, the anchoring zones 71, 72 are located on either side of the feed zone 30, in the axial direction. The wells 71, 72 are for example intended to receive rings for the suspension of the ammunition 10 to the transport platform.

An explosive charge 40, illustrated on figures 2 and 3 fills the front space of the ammunition 10 delimited by the inner wall of the body 12 and the front sheath 23, over a length L1 measured from the front end 12a of the ammunition 10. The explosive charge 40 is not in direct contact with the firing device 20 which is, as described above, located at the rear end 12b of the body 12.

In the illustrated example, the length L1 represents a little more than a third of the total length L of the munition 10 (see FIG. figure 3 ).

The explosive charge 40 may consist of a composite, in particular based on aluminum (Al), hexogen (RDX) and a polyurethane binder. An example of a composition that can be used is that referenced PBXN-109. Any other suitable composition may, however, be suitable.

An inert filler 50, having a density identical to or substantially identical to that of the explosive charge 40, is interposed between the explosive charge 40 and the rear sheath 21. The inert filler 50 may be a suitable plastic material, in particular a polyurethane matrix material. comprising a mineral filler.

In the example, the explosive charge 40, the inert charge 50 and the firing device 20 are therefore located one after the other in the direction of the axis A-A ', in this order inside the body 12 of the ammunition. In particular, in the example, the interface 52 between the explosive charge 40 and the inert charge 50, represented on the figures 1 and 3 , extends perpendicularly to the axis A-A '. The rear sheath 21 and thus the firing device 20 are furthermore surrounded by the inert filler 50.

As illustrated on the figure 3 , the explosive charge 40 is connected to the firing device 20 by pyrotechnic transmission means here comprising two pyrotechnic transmission units 60 passing through the inert filler 50.

In the example, the two transmission units 60 are arranged symmetrically on either side of the axis A-A 'and each extend parallel to this axis.

Each pyrotechnic transmission unit 60 here comprises a first end or front end in the form of a first priming relay 66 coupled with the explosive charge 40, a second end or a rear end in the form of a second priming relay. 62 coupled to the firing device 20 of the ammunition 10, and a pyrotechnic extender 64 interconnecting the two aforementioned ends.

This pyrotechnic extender 64 is an elongated element: it is therefore essentially directed along its main axis, or longitudinal axis, along which its length can be measured and which in the illustrated examples is parallel to the axis AA 'of the body 18, and which can be confused with it (non-illustrated case with a single pyrotechnic transmission unit 60 coaxial with the body 12).

The width of the pyrotechnic extender 64 is defined as the maximum radial dimension, that is to say the largest dimension measured in cross section, that is to say perpendicular to its main axis.

The first priming relay 66, the extension 64 and the second priming relay 62 may for example consist of an outer sheath of metal or plastic, filled with an explosive compound for transmitting the detonation of the setting device. to fire 20 to the explosive charge 40.

In the example shown on the Figures 1 to 3 , the second priming relay 62 is fitted around the rear sheath 21 and therefore in direct contact therewith. In particular, the sheath 21 has a substantially cylindrical shape, and the second priming relay 62 has a complementary shape, in particular ring portion, allowing it to marry the contour of the sheath. In this case, the sheath 21 has a thickness sufficiently small for a detonation to propagate by influence from the firing device 20 to the pyrotechnic transmission unit 60.

The function of the second priming relay 62 is here to increase the surface of the detonation wave coming from the firing device, to guarantee its good subsequent transmission.

According to another example, in the absence of a rear sheath 21, or if the rear sheath 21 has at least one opening leaving a partial glimpse of the firing device 20, the second priming relay 62 could also be directly in contact with the firing device 20.

According to yet another example illustrated on the figure 8 , the pyrotechnic transmission unit 60 can be separated from the sheath 21 or, in the absence of sheath 21, the firing device 20, by a layer of inert material, in particular an inert material forming part of the inert load 50. In this case, the thickness of the layer of inert material is sufficiently fine so that the detonation initiated by the firing device 20 can propagate by influence into the pyrotechnic transmission unit 60 and thus up to the explosive charge 40. Preferably, the thickness of the layer of inert material does not exceed 30mm.

In the example, the pyrotechnic extender 64 comprises a rigid tube, of constant diameter, filled with explosive.

Still in the example, the first priming relay 66 has a frustoconical shape, flared towards its free end, which allows the conformation of the detonation wave coming from the firing device 20 and transmitted by the pyrotechnic extender 64 until at the first priming relay 66, for example increasing its diameter for more effective detonation of the explosive charge.

The first priming relay 66, in particular its flared end, is here embedded inside the explosive charge 40.

According to another variant illustrated on the figure 5 , the first priming relay 66 can be connected to the explosive charge 40 by simply being pressed against the free surface of said explosive charge 40, in particular by its flared end.

According to yet another variant illustrated on the figure 6 , the first priming relay 66 can be bonded to the explosive charge 40 by a layer of adhesive 91 disposed between the surface of the explosive charge 40 and a surface of the ignition relay 66, in particular its end surface of which the section here is the largest.

According to yet another variant illustrated on the figure 7 one or each pyrotechnic transmission unit 60 may be coupled to the explosive charge by a layer of inert material 92 constituting the inert filler 50, said layer 92 being thin enough to allow the propagation of the detonation.

Note that the second priming relay 62, the pyrotechnic extender 64 and the first priming relay 66, described above, may be replaced by any other element allowing the transmission of a detonation between the firing device and the explosive charge. The characteristics described above in connection with the pyrotechnic transmission units 60 remain applicable to any other pyrotechnic transmission unit having a shape or a configuration different from those described and / or illustrated, remaining within the limits of the invention such that defined in the claims of this patent application.

In the example illustrated, the inert load 50 drowns, surrounds or surrounds all or part of the pyrotechnic transmission units 60 and in particular the pyrotechnic extender 64. It will be noted that according to an exemplary embodiment not illustrated, at least one pyrotechnic transmission unit 60 (and its pyrotechnic extender 64) could bypass the inert load 50 and couple the firing device 20 to the explosive charge 40 by passing through a gap formed between the inert load 50 and the inner face of the munition body 12.

Moreover, if in the example illustrated, the inert filler 50 fills the entire volume situated between the explosive charge 40 and the rear sheath 21 receiving the firing device 20, thus surrounding a portion of said sheath 21, it is also possible that a free space is maintained between the inert load 50 and the rear of the munition, and more particularly between the inert load 50 and the rear sheath 21 or the firing device 20. Such an embodiment is illustrated in FIG. figure 9 .

An exemplary implementation of the method of manufacturing a munition 10 as defined above will now be described in more detail.

In a first step of the method illustrated on the Figure 4A an elongated body 12 as described above and shown on the figure 1 . The body 12 is empty and has an opening 19 at least at its rear end 12b. In the example, as indicated above, the body 12 also has an opening 18 at its front end 12a.

In a second step illustrated on the Figure 4B the front sheath 23 and the electrical conduits 31, 32 are introduced and placed inside the body 12.

In the example, the front sheath 23 then closes the opening 18 formed at the front end 12a of the body 12.

The first electrical duct 31 is connected to the front duct 23 and then to the supply zone 30. The second duct 32 is connected at one of its ends to the supply zone 30. Its other end is free and, from by the rigidity of the conduit 32, is maintained in the vicinity of the rear opening 19.

Optionally, prior to this second step, the inner wall of the body 12 is coated with a linker.

In a third step of the process illustrated on the figure 4C a pasty explosive compound 40 is poured through the opening 19 into the body 12. To facilitate this step, the body 12 is preferably placed in a vertical position, its forward end 12a directed downwards. In this way, the explosive compound 40 fills the front part of the body 12, notably surrounding the front sheath 23 and part of the first duct 31.

In a fourth step of the method illustrated on the figure 4D , while the explosive compound 40 is still in the pasty state, the two pyrotechnic transmission units 60 are introduced inside the body 12 and placed therein so that one end of each of them, in particular the first priming relay 66 and possibly a section of the pyrotechnic extender 64, is embedded in the explosive compound 40.

In a fifth step of the method, the pyrotechnic transmission units 60 are held in position inside the body by suitable setting tools 84.

In a sixth step of the method, the body 12, including the pasty explosive compound 40, is conditioned to ensure the solidification of said compound 40 and the obtaining of a solid explosive charge adhering to the inner wall of the body 12. When the explosive compound 40 contains a crosslinkable binder and its crosslinker, the solidification occurs by crosslinking the binder. When, according to one variant, the explosive compound 40 is melted, the solidification is obtained by lowering the temperature.

The solidification of the explosive compound ensures the imprisonment of the end (the first priming relay 66 and possibly a section of the pyrotechnic extender 64) of each pyrotechnic transmission unit 60 in the mass of the explosive charge 40.

At this point, the wedging tools of the pyrotechnic transmission units 60 can be extracted or left in place if they can be dismantled during subsequent steps of the process.

In a seventh step of the process illustrated on the figure 4E , the rear sheath 21 is previously disposed at the desired location and then an inert material 50 is introduced into the remaining free internal volume of the body 12 of the munition, so that it comes into contact with the free surface of the explosive charge 40 , traps the pyrotechnic transmission units 60 and surrounds the rear sheath 21.

The inert material 50 is cast in the pasty state and then solidified, for example by crosslinking, in the free internal volume of the body 12.

The process is continued in an eighth step illustrated on the figure 4F , in particular being able to be performed during a subsequent use of the munition. A firing device 20 is attached to the interior of the rear sheath 21 and a functional member 22 of the ballistic control member type is housed in the front sheath 23. The functional member 22 is then connected to the first duct 31 and the firing device 20, the second conduit 32.

Finally, the opening 19 located at the rear end 12b of the bomb body 12 is closed by a nut 74.

The implementation example described above is however not limiting. The following variants, in particular, may be considered.

According to a first variant embodiment, the explosive pasty compound 40 may be solidified before the introduction of the pyrotechnic transmission unit or units 60 into the body 12 of the munition 10.

According to a second variant of implementation, the explosive charge 40 may be in the form of a preformed block adapted to be introduced inside the body 12 of the munition and to cooperate in complementary form with the internal walls of the this last.

In these two cases, each transmission unit 60 can be glued, in particular by its end (the first ignition relay 66 or in the absence thereof, the pyrotechnic extender 64), on the free surface of said load explosive 40.

The pyrotechnic transmission units 60 may also simply be in contact with the explosive charge 40 or positioned at a short distance therefrom. In this case, the inert load 50 can thus be introduced before the pyrotechnic transmission units 60, especially if it is introduced into the body 12 in a not yet solidified state. Thus, according to an exemplary implementation, the explosive charge is first put in place and solidified, then the inert charge is cast in the pasty state, and the pyrotechnic transmission unit 60 is introduced so that its end on the side of the explosive charge 40 (the first ignition relay 66 or in the absence of the latter, the pyrotechnic extender 64) comes into contact with the explosive charge 40 or so that this end is placed in the vicinity said explosive charge 40 being separated by a thin layer of inert material, in particular less than or equal to 30 mm.

According to a third variant of the method, at least one empty tube is positioned longitudinally in the body of the empty ammunition, one of its ends immersed in the body 12 to the level provided for the explosive material 40, the other end being located in rear portion for connection with the firing device 20. A pasty explosive compound 40 is then poured via said tube to fill a volume in the front area of the ammunition (expected volume for the explosive charge) and the internal volume of the tube. It is understood in this case that the viscosity of the paste must be sufficiently low to be able to ensure the flow of the paste in the tube, said tube forming at least one section of the pyrotechnic extender 64 and possibly the first priming relay 66.

The body 12 of the munition is then conditioned to obtain the curing of the pasty explosive material 40. After solidification, the tube is either left in place or extracted. A monolithic block is thus obtained consisting of the explosive charge 40 at the front of the ammunition 10 extended by a bar of explosive, possibly contained in the tube if it is left in place, constituting all or part of the transmission unit. pyrotechnic 60. The following steps are identical to those described above in connection with the first example of implementation of the method.

According to a fourth variant of the method, when the architecture of the munition body 12 allows it, the explosive charge 40 and the pyrotechnic transmission unit or units 60 constitute a preformed assembly (for example obtained by forming in a mold). This assembly is introduced and adhered in the body 12, and cooperates by complementary shape with the inner surface of the front portion of the body of the munition 12. The following steps are identical to those described above in connection with the first example of implementation. process.

Claims (15)

1. Munition (10) comprising an elongate casing (12) extending along an axis (A-A') and housing an explosive charge (40) and an inert charge (50), and further comprising a firing device (20), the munition being characterized in that at least a portion of the inert charge (50) is interposed between the firing device (20) and said explosive charge (40), and in that said munition further comprises at least one pyrotechnic transmission unit (60) provided with a pyrotechnic extension (64), said pyrotechnic transmission unit (60) coupling the firing device (20) to the explosive charge (40) to allow said explosive charge (40) to be detonated by the action of the firing device (20).
2. Munition (10) according to claim 1, wherein the firing device (20) is positioned at its rear end and the explosive charge (40) is positioned at its front end.
3. Munition (10) according to claim 1 or 2, wherein the pyrotechnic transmission unit is at least partially embedded in the inert charge.
4. Munition (10) according to any of claims 1 to 3, wherein the explosive charge (40), the inert charge (50) and the firing device (20) are situated inside the casing (12) in that order one after the other in the axial direction of said casing (12), the explosive charge (40) being closest to the front of the munition (10).
5. Munition (10) according to any of claims 1 to 4, comprising at least two pyrotechnic transmission units (60) spaced apart from each other.
6. Munition (10) according to any of claims 1 to 5, wherein the pyrotechnic extension (64) is formed by a rigid or flexible tube containing an explosive compound.
7. Munition (10) according to any of claims 1 to 5, wherein the pyrotechnic extension (64) is formed by a rigid cord of any shape, produced from an explosive compound.
8. Munition (10) according to any of claims 1 to 7, wherein the pyrotechnic extension (64) has a maximum radial dimension that is at least 5 times smaller than the maximum diameter of the munition, preferably at least 20 times smaller than said diameter.
9. Munition (10) according to any of claims 1 to 8, wherein the pyrotechnic extension is longer than it is wide, in particular at least 10 times longer than it is wide, preferably at least 20 times longer than it is wide.
10. Munition (10) according to any of claims 1 to 9, wherein the length of the pyrotechnic extension is at least 1/2, preferably at least 2/3, the total length of the munition.
11. Munition (10) according to any of claims 1 to 10, wherein the pyrotechnic transmission unit (60) further comprises a first booster (66) coupling said pyrotechnic extension (64) to the explosive charge (40).
12. Munition (10) according to claim 11, wherein the first booster (66) is separated from the explosive charge (40) by a layer of inert material, in particular a layer of inert material forming part of the inert charge (50).
13. Munition (10) according to any of claims 1 to 12, wherein the pyrotechnic extension (64) comprises a single explosive compound of homogeneous composition.
14. Filler material for integration into a munition according to any of claims 1 to 13, comprising an explosive charge (40) and an inert charge (50), and further comprising at least one pyrotechnic transmission unit (60) provided with a pyrotechnic extension, said pyrotechnic transmission unit being adapted to transmit a remotely initiated detonation to said explosive charge (40) from the end of the inert charge (50) remote from said explosive charge (40).
15. Method of manufacturing a munition (10) according to any of claims 1 to 13, characterized in that it comprises at least the following steps:

    a) providing an elongate hollow casing (12) including at least one inlet opening (19) at one of its ends (12b);

    b) introducing an explosive charge (40), an inert charge (50) and at least one pyrotechnic transmission unit (60) provided with a pyrotechnic extension (64) into the casing (12) in a manner such that the pyrotechnic transmission unit (60) is coupled to the explosive charge (40); and

    c) coupling the pyrotechnic transmission unit (60) to a firing device (20);

    the inert charge (50) then being interposed between the firing device (20) and said explosive charge (40), and the pyrotechnic transmission unit enabling said explosive charge (40) to detonate under the action of the firing device (20).

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