ES2657804T3 - Two-component explosive artillery howitzer - Google Patents

Abstract

Two-component explosive artillery howitzer (1) comprising a wrapper (2) containing at least two non-explosive materials (3, 4) but which after mixing form an explosive composition, howitzer comprising at least one container (8) fixed to the envelope (2) and coaxially disposed thereto, container that delimits an internal cavity (12) containing a first material (3) in liquid or gelled form, container (8) whose wall (8a) is perforated by a plurality of holes (15) which are closed by means of a sealing means (16), where the container (8) delimit with the envelope (2) an annular space (18) that encloses a second material (4) in solid and porous form, where the sealing means (16) can be opened during shooting to allow diffusion by centrifugal effect of the first material (3) in the second material (4) through the porosity of the latter, howitzer characterized by the fact that it comprises at least one stack of conte nedores (8) aligned axially and joined to each other, where each container is separated from its neighbors by at least one transverse wall (13), or comprising a single cylindrical container (8) extending axially along of the entire height of the second material (4), where this container is compartmentalized and comprises transverse partitions that divide its internal volume into several chambers.

Description

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DESCRIPTION

Two-component explosive artillery howitzer

[0001] The technical field of the invention is that of explosive artillery shells and, in particular, that of two-component explosive shells.

[0002] Traditionally, explosive shells enclose an explosive charge comprising a fuse explosive such as trinitrotoluene (TNT) associated with one or more complementary grain explosives such as hexogen (RDX) or oxynitrotriazole (ONTA).

[0003] Traditionally, the explosive starts in trajectory or on the impact of a fuze.

[0004] When the fuze does not work, the shells remain on the ground in an untapped state and constitute a danger. Indeed, they can be reused by enemies in the form of improvised explosive devices.

[0005] To mitigate this risk, it is convenient to define a howitzer whose load can be automatically neutralized after a certain period of time in case of non-initiation.

[0006] Two-component called explosives have been known for a long time. Each component alone is not explosive, which means that the installation of a detonator cannot cause its detonation. The mixture of the two materials, on the other hand, is explosive and can be detonated by the action of a suitable detonator.

[0007] Patent US4253889 thus describes two-component explosives that are used in mines and quarries. The two components are mixed by an operator before use, which allows to store components that individually do not pose any danger.

[0008] It is also known that these two-component explosives can be made inert by the action of particular additives. Patent FR2289472 thus describes a liquid explosive composition based on nitromethane which is sterilized after a few hours when mixed with diethylenetriamine.

[0009] However, there is no known specific application of such two-component explosives in shells or shells.

[0010] Patent FR994041 describes pumps or projectiles with two-component explosive. However, these projectiles use liquid materials that mix in the path. It is necessary to break the envelope containing one of the materials to mix it with the other material. The fragile wrap is made of glass or ceramic, for example. This architecture is complex and expensive.

[0011] In addition, an explosive liquid charge is poorly adapted to a projectile shot by cannon effect, taking into account the vortex effects that can occur in the liquid charge, which decrease the stability of the projectile in ballistic flight.

[0012] A projectile that can enclose several charges with different effects is known from WO2010 / 044716. This document explains that it is possible to associate a liquid oxidizing material placed in an axial container and a porous fuel. The axial container also encloses an initiation means in the form of threads that extend longitudinally over the entire container. With such a projectile, the axial inertia efforts that take place at the time of the shot in the liquid material will cause premature breakage, at the rear of the container, of the plastic films that seal the radial holes of the container. The reaction between the components will then take place inside the gun tube itself, before the projectile is rotated and not homogeneously, with the films breaking only on the back of the container.

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[0013] The aim of the invention is to propose a two-component artillery howitzer that has a simple, inexpensive conception, reliable operation and ensures a shot without ballistic disturbances.

[0014] The invention thus allows defining a howitzer that does not contain products that are considered individually explosive. This means an increase in security in the transport and logistics phases.

[0015] According to a particular embodiment, the invention also allows defining an artillery howitzer whose explosive charge can be sterilized after a certain period of time in case it does not explode on an objective.

[0016] Thus, the invention has as its object a two-component explosive artillery howitzer comprising a shell containing at least two non-explosive materials but which, after mixing, forms an explosive composition, said howitzer comprises at least one fixed container to the envelope and coaxially disposed thereto, said container delimits an internal cavity containing a first material in liquid or gelled form, where the wall of said container is perforated with a plurality of holes closed by a sealing means, the container (s) they delimit with the envelope an annular space that encloses a second material in solid and porous form, where the sealing means can be opened at the time of the shot to allow diffusion by centrifugal effect of the first material in the second material through the porosity of the latter, the howitzer is characterized by the fact that it comprises at least one stack of alin containers axially and joined to each other, where each container is separated from its neighbors by at least one transverse wall, or by the fact that it comprises a single cylindrical container that extends axially over the entire height of the second material, said container It is compartmentalized and comprises transverse partitions that divide its internal volume into several chambers.

[0017] According to a particular embodiment, the sealing means may be constituted by at least one sheet fixed to the wall, said sheet is capable of breaking at the time of the shot to allow the first material to pass.

[0018] The container (s) may be cylindrical or conical shaped.

[0019] According to another embodiment, the howitzer may contain at least two cylindrical containers of different diameters that follow each other along the axis of the howitzer.

[0020] Advantageously, the containers may be placed with respect to the wrap by means of at least one radial wedge.

[0021] The second material may comprise at least one oxidant, such as potassium perchlorate, ammonium perchlorate, ammonium nitrate or potassium nitrate.

[0022] The first material may comprise at least one aliphatic nitro hydrocarbon, such as nitromethane or nitroethane.

[0023] According to a particular embodiment, the howitzer may contain at least one sterilization material of the first material

[0024] The sterilization material may comprise at least one of the following materials: ethylenediamine, diethylenetriamine.

[0025] Advantageously, the sterilization material may be installed in at least one housing.

[0026] The invention will be better understood by reading the following description of particular embodiments, the description is made in reference to the attached drawings, in which:

- Figure 1 is a longitudinal sectional view of a howitzer according to a first embodiment of the invention, with an uncut axial container;

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- Figure 2 is a view analogous to the preceding one, but shows the cut axial container;

- Figure 3 is a longitudinal sectional view of a howitzer according to a second embodiment of the invention, with a cut axial container;

- Figures 4a and 4b are schematic views of two other embodiments of an axial container, Figure 4a shows a container in external view and Figure 4b a container in longitudinal section;

- Figure 5 is a partial schematic view of a stack of containers incorporating a housing for the sterilization material.

[0027] Referring to FIG. 1, an explosive artillery howitzer 1 according to the invention comprises a shell 2 containing at least two non-explosive materials 3, 4 but which after mixing form an explosive composition.

[0028] The envelope 2 is constituted here by two parts: an ogival front part 2a and a cylindrical rear part 2b. This type of arrangement is intended to facilitate the loading of howitzer 1 with the materials 3 and 4.

[0029] The wrap 2 is closed at its back by means of a bib 5 that is fixed to the wrap 2, for example by rivet.

[0030] The envelope 2 carries a fuse 6 of the traditional type to its front, for example a percussion, proximity or chronometric fuse.

[0031] In the figures it can be seen that the bib 5 has a device 7 which may be a discounted bib device (better known by its Anglo-Saxon denomination "base bleed"). The device 7 may simply be a hollow shorts. This device is not part of the invention.

[0032] In accordance with the invention, howitzer 1 includes at least one container 8 that is attached to the shell 2 and coaxially disposed thereto.

[0033] Howitzer 1 includes here a stack of six cylindrical containers 8 and all have axis 9 of howitzer 1 per axis.

[0034] All containers 8 have an identical structure and, as seen more particularly in Figure 2b, each includes a tubular wall 8a delimiting an internal cavity 12 containing the first material 3, which is in a liquid form or gelled

[0035] Each container 8 includes a closed transverse wall or bottom 13 sealed by a lid 14 that is screwed to the tubular wall 8a. The tubular wall 8a is perforated by a plurality of radial holes 15 closed by sealing.

[0036] According to the embodiment shown, the sealing means is constituted here by a sheet 16 fixed to the tubular wall (for example glued to the wall 8a). The sheet will, for example, be a 0.1 mm thick sheet of a plastic material such as polyethylene.

[0037] The tubular wall 8a extends to the rear of the container 8 by means of a cylindrical collar 8b which is housed on a cylindrical bearing 14a of the cap 14 of a neighboring container. The container 8 which is located at the rearmost part of the howitzer in its cylindrical collar 8b which is placed in a circular groove 10 of the shell 5 of the howitzer. The collar 8b and the bearing 14a may have external and internal threads.

[0038] Slot 10 allows radially positioning the stack of containers with respect to shell 2 of the howitzer. The bib 5 ensures axial maintenance, this axial maintenance is completed by a ring 17 that is screwed to the opening of the howitzer 1 and also receives the fuze 6. The ring 17 rests against the plug 1 4 of the container 8 in the part more forward of the howitzer.

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[0039] The stack of containers 8 is also placed radially with respect to the shell 2 of the howitzer by means of two radial wedges 11. The radial wedges 11 will be made, for example, of plastic material, for example of polyamide.

[0040] They will be advantageously perforated by holes parallel to the axis 9 of the howitzer to facilitate the distribution of the liquid material 3, as will be explained later.

[0041] This embodiment of an identical stack of containers 8 makes it easier to manufacture and integrate the howitzer. In addition, the transverse or bottom walls 13 and the covers 14 form partitions that allow insulating the material contained in each container 8 from that of the neighboring containers. This type of arrangement reduces the influence on the first material 3 of the axial acceleration exerted during the shot.

[0042] This reduces the pressure differential that may appear inside a container 8 between the bottom 13 of the container and the part of the container near its cap 14.

[0043] Instead of having a single column of first liquid material that would undergo axial acceleration, here are as many columns of the first material as containers and the pressure differential is the same inside each container.

[0044] This also makes it possible to avoid premature rupture of the sheets 16 that seal the holes closest to the bib 5 only by the effect of axial inertia. This results in greater reliability of operation. Indeed, the rupture of the sheets does not take place asymmetrically and before the rotation of the howitzer. A break caused solely by axial inertia would lead to premature mixing of the first material 3 with a second material 4 only at the rear of the howitzer and in the tube of the weapon.

[0045] The containers 8 delimit an annular space 18 with the envelope 2 containing a second material 4 in solid and porous form.

[0046] The second material 4 may be made in the form of compressed annular blocks, for example. The granulometry of the grains that constitute the second material, as well as the compressive stresses will be chosen so as to ensure the desired porosity.

[0047] As can be seen in Figures 1 and 2a, for example, two annular blocks 4a and 4b separated by a wedge 11 may be placed in the cylindrical part 2a of the envelope 2. The stack of containers 8 will be placed at then in the axial channel of the annular blocks 4a, 4b.

[0048] A third block 4c of the second material 4, made in the internal profile of the ogival part 2b of the envelope, will then be placed in this ogival part 2b. Further on, the ogival part 2b will be fixed to the cylindrical part 2a of the envelope 2 with the interposition of a second wedge 11.

[0049] The first material 3 is a fuel or a mixture of liquid or gelled fuel. It may comprise at least one aliphatic nitro hydrocarbon, such as nitromethane or nitroethane.

[0050] The substances commonly used in the formulation, of mineral or organic origin, such as silica fumes, natural or synthetic gums, polymers or any other appropriate substance may be chosen as gelling agents.

[0051] The first material 3 may comprise a sensitizer associated with aliphatic nitro hydrocarbon. However, it will be necessary that this sensitizer has no effect of sterilization of the hydrocarbon.

[0052] The second material 4 comprises at least one strong oxidant, that is, a compound capable of transferring oxygen to the reactive medium, such as potassium perchlorate, ammonium perchlorate, ammonium nitrate or potassium nitrate. The grains of this material may be coated with a binder, for example an inert binder such as wax or an active binder such as DNAN (2,4-dinitroanisole), which is a low sensitive explosive.

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[0053] The binder will facilitate the compression installation of the blocks of the second material 4.

[0054] According to a particular embodiment, in order to allow the sterilization of the explosive material in case of impact with the ground without detonation, a sterilization material of the first material may be provided.

[0055] The sterilization material will comprise, for example, at least one of the following materials: ethylenediamine, diethylenetriamine. These materials are liquids at usual use temperatures. The sterilization material will therefore be installed in a specific housing (not shown) that will allow it to be isolated from the first material 3 and that will break at the time of shooting.

[0056] This specific housing may, for example, be placed between the ring 17 and the stack of containers 8.

[0057] Advantageously and, as shown in Figure 5, the sterilization material 24 may be installed in at least one specific housing 25 which will be fixed to the container stack 8 containing the first material 3. This housing 25 will have the same diameter as the containers 8 and will be provided with a cap 26 and a bottom 27 analogous to the caps 14 and to the transverse walls or bottom 13 of the containers 8 (and eventually will also have outer and inner threads to secure it to the containers) .

[0058] In this way, the housing 25 can be placed in any axial position on a stack of containers 8. It can, for example, be placed at the head of the stack, near the ring 17. It can also be placed as shown in Figure 5, between two containers 8.

[0059] The housing 25 will have the holes 28 which will be closed by a seal formed, for example, by the sheet 16 surrounding the stack of containers 8.

[0060] One or more housings 25 containing the sterilization material may be provided.

[0061] It is necessary to provide an amount of sterilization material equal to approximately 5% of the total mass formed by the first material and the sterilization material.

[0062] This reduced quantity may be distributed in several housings 25 whose size will therefore be much smaller than that of the containers 8 containing the first material 3.

[0063] It may alternatively be grouped into a single housing 25 of larger size (but smaller than that of a container 8).

[0064] In addition, the dimensions of the containers 8 will be defined as a function of the relative volumes desired for the first material 3 and the second material 4. A configuration such as that shown in Figures 1 and 2a corresponds to a relative volume that it is about 20% for the first material 3 and 80% for the second material 4. The porosity of the second material 4 is chosen so that it represents a sufficient volume to accommodate the first material. The air contained in the second material 4 will circulate within the porous blocks and will eventually occupy the internal volume of the containers 8 after ejection of the first material. To facilitate the circulation of the first material 3, a partial emptying of the air from the shell can be provided during assembly.

[0065] The operation of this howitzer is as follows.

[0066] During the storage phases of howitzer 1, the first and second material 3 and 4 are isolated from each other. Howitzer 1 is, therefore, completely inert and can be transported without any danger.

[0067] During the shooting, the important rotation speed communicated by the striped tube of the weapon to the howitzer thanks to the forcing band 19 will evacuate radially by the effect of centrifugal force the first material 3 out of the containers 8, through the holes 15. The efforts of inertia

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centrifuge will ensure the breakage of the sheet 16 for each container 8. It is sufficient to define the thickness of the sheet 16 based on the desired mechanical strength.

[0068] In addition, and if such a material is provided, inertial efforts will ensure ejection of the sterilization material out of the housing (s) 25.

[0069] The level of efforts is sufficient to ensure the mixing and distribution of all liquid components in the porous matrix.

[0070] Once the sheets 16 have been broken, the diffusion of the first material 3 into the second material 4 takes place through the porosity of the latter. Centrifugal inertia forces accelerate this diffusion. The air evacuated from the porosity will be concentrated inside the emptied containers 8.

[0071] Once the two materials 3 and 4 have been mixed, the composition formed by the mixture of these two materials is detonating. The eventual sterilization material 24 ensures a sensitization effect of the first material 3 for a limited duration.

[0072] Traditionally, this composition is initiated by fuze 6 of the howitzer.

[0073] By way of example, a composition that associates 70% by mass of potassium perchlorate and 30% by mass of nitromethane has a detonation rate of 6100 to 6200 m / s. Which is of the same order as the TNT (6900 m / s).

[0074] It should be mentioned that the sterilization material also has a sensitization effect lasting at least one hour. Sterilization only intervenes after a duration of more than 3 hours depending on the amount of sterilization material applied.

[0075] When the fuze 6 does not work and the howitzer remains on the ground, the explosive charge ends up being sterilized. The duration of the reaction between the sterilization material and the first material is compatible with the operational needs.

[0076] This will ensure neutralization of the explosive charge in case there is no detonation on a target. The shells that have not exploded will, therefore, be inert and may not be used as improvised explosive devices.

[0077] Various variants are possible without departing from the scope of the invention.

[0078] It is possible, as shown in FIG. 3, to dispose in the shell 1 at least two cylindrical containers 8 of different diameters that follow each other along the axis of the howitzer.

[0079] According to the embodiment shown in FIG. 3, there is a first stack of three large diameter containers 81 extending from the culot 5 of the howitzer 1 to an intermediate zone Z of the howitzer, and there is a second stack of three small diameter containers 82 extending from the intermediate zone Z of the howitzer to the ring 17.

[0080] A first wedge 11 holds the first stack radially. A second wedge 11 holds the second stack radially.

[0081] Containers 81 and 82 have approximately the same structure as the container previously described in reference to Figure 2b. The container 81 that is further back is housed in a groove 10 of the bib 5. The small diameter container 82 that is further back is housed in a groove 20 disposed in the lid 14 of the large diameter container 81 on which it is installed. As previously described, ring 17 ensures axial immobilization of the container stack.

[0082] This embodiment allows for a different volume and mass ratio for the first material and for the second. Thus, the configuration according to Figure 3 allows a volume ratio of 30% for the first material and 70% for the second material.

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[0083] It is also possible to provide with this embodiment one or more housings containing a sterilization material (not shown in the figure).

[0084] The container (s) 8 may have a different shape, for example conical trunk. Figure 4a thus shows schematically a stack of truncated conical containers 8 whose diameters increase progressively from back to front. The larger diameter container is positioned against the shell 5 of the howitzer, for example.

[0085] Figure 4b shows another embodiment of a single container 8 that is intended to extend axially over the entire height of the second material 4.

[0086] This container is compartmentalized and includes the transverse partitions 21 that divide the internal volume of the container 8 into several chambers 22. In order to allow the arrangement of the first material 3 in the container 8, each partition 21 includes an axial hole 23 communicating the chambers 22. The container is closed by a cap 14 and has a bottom 13. A sheet 16 wrapped around the container 8 seals the holes 15.

[0087] The partitions 21 make it possible to reduce the pressure gradients between the upper part and the lower part of the container 8. In this way, the stresses that would be transmitted to the sheet 16 as a continuation of the axial inertia forces are reduced.

[0088] As in the previous embodiment, a breakage of the sheets asymmetrically and before the rotation of the howitzer is rotated is avoided. Premature mixing of the first material with the second material is avoided only at the rear of the shell and in the tube of the weapon.

[0089] The embodiments of the invention in which the hole sealing means is constituted by a sheet that is perforated during shooting by the effect of centrifugal exertions exerted on the first material have been represented here.

[0090] It is possible to define one or more containers in which the holes are closed by a sealing means of different structure.

[0091] For example, fragmentable plugs may be provided by centrifugal efforts.

[0092] A container may also be made whose holes are not uncovered, but are closed by a thinned part of the tubular wall of the container. These thinned parts form more fragile areas of the tubular wall of the container that will be broken by the effect of centrifugal stresses during firing by the first material.

[0093] Thus, it is possible to provide simple precuts or more fragile areas in the wall of the containers at the height of the holes.

[0094] Of course, these structural modifications are also possible to define the means of sealing the holes of the housing (s) 25 where the sterilization material 24 is located.

[0095] A howitzer was described in which a sterilization means was provided.

[0096] Of course, it is possible to define a howitzer according to the invention that does not comprise the sterilization material.

[0097] A two-component howitzer will, however, have greater transport safety than that of conventional explosive shells because the materials it contains are not in themselves and individually considered as explosive materials.

Claims (11)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty REIVINDICA CIONES 1. Artillery howitzer (1) two-component explosive comprising a shell (2) containing at least two non-explosive materials (3, 4) but which after mixing form an explosive composition, howitzer comprising at least one container (8) fixed to the envelope (2) and coaxially disposed thereto, container that delimits an internal cavity (12) containing a first material (3) in liquid or gelled form, container (8) whose wall (8a) is perforated by a plurality of holes (15) that are closed by means of a sealing means (16), where the container (8) delimit with the envelope (2) an annular space (18) that encloses a second material (4) in solid form and porous, where the sealing means (16) can be opened during shooting to allow diffusion by centrifugal effect of the first material (3) in the second material (4) through the porosity of the latter, howitzer characterized by the fact of comprising at least one stack of co containers (8) aligned axially and joined to each other, where each container is separated from its neighbors by at least one transverse wall (13), or of which it comprises a single cylindrical container (8) extending axially along of the entire height of the second material (4), where this container is compartmentalized and comprises transverse partitions that divide its internal volume into several chambers. 2. Explosive artillery howitzer according to claim 1, characterized in that the sealing means (16) is constituted by at least one sheet fixed to the wall (8a), said sheet is capable of breaking at the time of shooting to pass the first material. 3. Explosive artillery howitzer according to one of claims 1 or 2, characterized in that the container (8) has a cylindrical shape. 4. Explosive artillery howitzer according to one of claims 1 or 2, characterized in that the container (8) has a frustoconical shape. 5. Explosive artillery howitzer according to claim 3, characterized in that it comprises at least two cylindrical containers (81, 82) of different diameters that follow each other along the axis (9) of the howitzer. 6. Explosive artillery howitzer according to one of claims 1 to 5, characterized in that the containers are arranged with respect to the envelope by at least one radial wedge (11). 7. Explosive artillery howitzer according to one of claims 1 to 6, characterized in that the second material (4) comprises at least one oxidant, such as potassium perchlorate, ammonium perchlorate, ammonium nitrate or potassium nitrate. 8. Explosive artillery howitzer according to claim 7, characterized in that the first material (3) comprises at least one aliphatic nitro hydrocarbon, such as nitromethane or nitroethane. 9. The explosive artillery howitzer according to claim 8, characterized in that it comprises at least one sterilization material (24) of the first material (3). 10. Explosive artillery howitzer according to claim 9, characterized in that the sterilization material (24) comprises at least one of the following materials: ethylenediamine, diethylenetriamine. 11. Explosive artillery howitzer according to one of claims 9 or 10, characterized in that the sterilization material (24) is installed in at least one housing (25).