EP0741856B1 - Anti-fragmentation covering for an armoured vehicle - Google Patents

Description

The technical field of the present invention is that of the splinter coatings that we place behind the wall of an armored vehicle to decrease his vulnerability.

The splinter coatings are mainly used today in vehicles armored personnel carriers or combat vehicles Infantry. Their function is to decrease the angle of the cone of flakes generated during the perforation of the armored vehicle with anti-tank projectile kinetic energy (arrow projectile) or especially jet of hollow charge. Having regard to the technical field concerned, we understands that there is very little data bibliographies describing these coatings.

We know, however, that we can have a composite panel with organic matrix and fibers organic (aramid or polyethylene) or mineral (glass) distant from 100 to 360 mm from the internal wall of the vehicle. The main disadvantage of this solution lies in its relatively large size leading to a sharp reduction in the internal volume of the vehicle.

We also know another technology consisting of placing against the internal wall of the vehicle a plate of solid organic material (polyethylene by example) about 50 mm thick, which absorbs partially the fragments produced by the wall. Through against, it generates by its aggression shards undetectable in the human body by radiographs.

We know the patent US-A-5,200,256 describing a multilayer assembly intended to stop small and medium caliber firearms, consisting of a first layer of steel, followed by a layer of composite material, metallic mesh and finally a layer of foam applied to the structure. This coating is placed outside the structure and constitutes the shielding itself and not a splinter-proof coating.

We also know the patent WO-A-91 00490 which describes a multilayer assembly also intended for stop small and medium caliber projectiles from analogous to the previous patent.

We still know the patent EP-A- 0 588 212 concerning a solid type splinter-proof coating, arranged as in the invention against the internal wall of a structure. The coating described, however, includes several layers made from the same constituents, i.e. an organic matrix in which incorporates tungsten particles. The impedance to the shock of the layers is decreasing, in other words the underlay placed against the structure has a high value close to that of the structure herself.

The object of the present invention is to offer a lightened splinter coating, offering a efficiency equivalent to that of solid coatings, but with a greatly reduced thickness, using materials with a density much lower than that metals.

The subject of the invention is therefore a splinter-proof coating for armored vehicles comprising in particular a layer adherent of solid organic material arranged against the inner wall of the vehicle, an adjacent layer of a composite material with organic matrix and mineral reinforcement or organic placed in the immediate vicinity of the layer adherent, characterized in that it is inserted between the adherent layer and the adjacent layer an area of thickness dispersion between about 5 and 30 mm filled with a liquid or gaseous fluid, or a foam polystyrene or polyurethane.

According to a characteristic of the invention, the adherent layer of solid organic material is chosen in the group consisting of polyethylene, the polypropylene, a plate of polyethylene filaments or of aramid, a rubber, and having a thickness between 2 and 45 mm.

According to another characteristic of the invention, the splinter-proof coating comprises a absorbent layer of particles chosen from the group consisting of a matrix and binder composite material organic and a plastic film of thickness included between about 1 and 5 mm.

According to one embodiment of the invention, the layer adjacent has a thickness of between about 2 and 30 mm.

• une couche adhérente de polyéthylène de 25 mm d'épaisseur,
• une zone de dispersion de 10 mm d'épaisseur,
• une couche adjacente d'un matériau composite à matrice organique renforcée par des fibres de verre, de 30 mm d'épaisseur, et
• une couche absorbante de polyéthylène bi-étiré de 2 mm d'épaisseur.

According to a preferred embodiment of the invention, the splinter-proof coating comprises:

• an adhesive layer of polyethylene 25 mm thick,
• a 10 mm thick dispersion zone,
• an adjacent layer of an organic matrix composite material reinforced with glass fibers, 30 mm thick, and
• an absorbent layer of bi-stretched polyethylene 2 mm thick.

• une couche adhérente de polyéthylène de 30 mm d'épaisseur,
• une couche adjacente d'un matériau composite à matrice organique renforcée par des fibres de verre de 35 mm d'épaisseur, et
• une couche absorbante de polyéthylène bi-étiré de 5 mm d'épaisseur.

According to a second embodiment of the invention, the splinter-proof coating comprises:

• an adherent layer of polyethylene 30 mm thick,
• an adjacent layer of an organic matrix composite material reinforced with glass fibers 35 mm thick, and
• an absorbent layer of bi-stretched polyethylene 5 mm thick.

• une couche adhérente constituée d'une première sous-couche de polyéthylène de 15 mm d'épaisseur environ et d'une seconde sous-couche de composite à matrice organique de 10 mm d'épaisseur environ,
• une zone de dispersion de 10 mm d'épaisseur environ remplie de mousse polyuréthane,
• une couche adjacente d'un matériau composite à matrice organique renforcée par des fibres de verre de 35 mm d'épaisseur environ, et
• une couche absorbante de polyéthylène bi-étiré de 5 mm d'épaisseur environ.

According to another alternative embodiment, the splinter-proof coating comprises:

• an adherent layer consisting of a first polyethylene sublayer approximately 15 mm thick and a second organic matrix composite sublayer approximately 10 mm thick,
• a dispersion zone of approximately 10 mm thick filled with polyurethane foam,
• an adjacent layer of an organic matrix composite material reinforced with glass fibers approximately 35 mm thick, and
• an absorbent layer of bi-stretched polyethylene approximately 5 mm thick.

An advantage of the present invention lies in absorbing the splinters generated during the perforation of the vehicle wall without production secondary flakes and simultaneously reducing or total suppression of the phenomenon of flaking at the opposite side of the structure to the attack.

Another advantage is the reduction in the size of the coating inside the vehicle.

Another advantage is the capacity of the coating according to the invention to reduce the neutron flux, and absorb the heat flux transmitted by them projectile fragments brought to high temperature to thereby ensuring a flame retardant effect.

Other features and benefits of the invention will appear more clearly on reading the additional description given below as indicative in relation to an attached drawing on which Figures 1 to 3 are sectional views of the coating according to the invention.

In Figure 1, there is shown in section the wall 1 of an armored vehicle or structure any splinters when it is damaged by a projectile coming from outside as this is symbolized by the arrow F. We place behind this wall 1, that is to say on the inside, a first adherent layer 2 made of a material known chosen from the group constituted by the polyethylene, polypropylene, a plate of filaments of polyethylene or aramid, a rubber. membership can for example be made by gluing using a glue or bolting. The thickness of this layer 2 is advantageously between 5 and 45 mm. The function of this layer, due to the thickness chosen, is to limit and / or stop the large flakes produced behind wall 1 and get a first reduction of the dispersion angle of the this armored wall. If applicable, this layer 2 ensures a decrease in the neutron flux inside of the vehicle in the event of a nuclear attack. When the layer 2 is in the form of a plate of organic polyethylene or aramid filaments, we plays on the large dynamic deformation capacity of this material.

This first layer is followed by a layer adjacent 3 which in combination with layer 2 stops the secondary flakes generated by the first layer and further reduces the scattering angle of the shards of the armored wall 1. This layer 3 consists of a composite material with organic matrix and mineral reinforcement with a thickness between 5 and 30 mm. The combination effects of layers 2 and 3 achieves with a markedly reduced thickness equivalent efficiency even higher than each of these layers taken in isolation, but with significantly more space important.

The effectiveness of these two layers 2 and 3 is supplemented by a third layer 4, called layer absorbent, to limit the projection of microparticles glass harmful to the human body inside the vehicle or structure during perforation. This layer 4 is made up of composite materials organic matrix and organic binder and / or film plastic with high mechanical characteristics such as bi-stretched polyethylene. The thickness of this layer 4 is weak compared to that of the other two, for example from 1 to 5 mm. This layer 4 is applied, for example by gluing, on layer 3.

We can further improve the performance of the splinter-proof coating according to the invention, spacing according to figure 2, layers 2 and 3 so as to create a layer or zone of dispersion 5 of the fragments. This layer 5 can be a gas or a liquid, a foam polystyrene or polyurethane, including thickness between 5 and 30 mm approximately. The presence of this layer 5 is conditioned by the level of threat you want reduce.

By way of illustration, the following two configurations have been made: Coating a Coating b layer 2 25 mm 30 layer 5 10 mm 0 layer 3 30 mm 35 layer 4 2 mm 5

Tests against perforations with a large gauge hollow charge have shown that the coating a of thickness 67 mm and the coating b of thickness 70 mm had an effectiveness equivalent to that of the known coatings of much larger dimensions and conforms to the desired performance.

Figure 3 illustrates a variant of realization of the splinter-proof coating in which the layer 2 is replaced by two sublayers 2a and 2b. The sublayer 2b is of the same nature as layer 2 previous, that is to say that it is constituted by polyethylene, polypropylene, filament board of polyethylene or aramid, a rubber. This material has a good shock impedance. She can present a thickness between 2 and 30 mm. The underlay 2b consists of an organic matrix composite with reinforcements of mineral or organic fibers. The thickness of this layer 2b is of the order of 2 to 20 mm. The layer 5 which constitutes a dispersion zone can be made of polystyrene foam or polyurethane. The other two layers 3 and 4 remain identical to the previous ones.

• couche 2a : 15 mm de caoutchouc,
• couche 2b : 10 mm de composite,
• couche 5 : 10 mm de mousse de polyuréthane,
• couche 3 : 30 mm de composite,
• couche 4 : 2 mm de polyéthylène bi-étiré.

By way of illustration, a splinter-proof coating has been produced comprising:

• layer 2a: 15 mm of rubber,
• layer 2b: 10 mm of composite,
• layer 5: 10 mm of polyurethane foam,
• layer 3: 30 mm of composite,
• layer 4: 2 mm of bi-stretched polyethylene.

Puncture tests with a shaped charge have shown the excellent behavior of the splinter-proof coating obtained.

In general, we note the flame retardant effect of coating according to the invention which does not catch fire under the effect of high-powered projectile shards temperature. This technical effect is due to the absence oxygen within the coating, at the particular choice of the nature of the layers and the good adhesion between these layers.

Claims (8)

1. A splinterproof lining for an armoured vehicle notably comprising a adhesive layer (2) of solid organic material placed against the inner wall (1) of the vehicle, an adjacent layer (3) made of a composite material with organic matrix and mineral or organic reinforcement placed in the immediate vicinity of the adhesive layer (2), characterised in that a dispersion zone (5) between approximately 5 and 30 mm thick filled with a liquid or gaseous fluid, or a polystyrene or polyurethane foam is inserted between the adhesive layer (2) and the adjacent layer (3).
2. A splinterproof lining according to Claim 1, characterised in that the adhesive layer (2) of solid organic material is chosen from the group made up of polyethylene, polypropylene, a plate of polyethylene or aramid filaments, a rubber, and is between 5 and 45 mm thick.
3. A splinterproof lining according to Claim 2, characterised in that the adhesive layer (2) is between 2 and 45 mm thick.
4. A splinterproof lining according to Claims 1 to 3, characterised in that it comprises an absorbing layer (4) of particles chosen from the group made up of a composite material with organic matrix and binder and a plastic film between approximately 1 and 5 mm thick.
5. A splinterproof lining according to one of Claims 1 to 4, characterised in that the adjacent layer (3) is approximatively between 2 and 30 mm thick.
6. A splinterproof lining according to Claim 5 characterised in that it comprises :

   an adhesive layer (2) of polyethylene 30 mm thick,

   an adjacent layer (3) made of a composite material with organic matrix reinforced by glass fibres, 35 mm thick, and

   an absorbing layer (4) of double-drawn polyethylene 5 mm thick.
7. A splinterproof lining according to Claim 5 characterised in that it comprises :

   an adhesive layer (2) of polyethylene 25 mm thick,

   a dispersion zone (5) 10 mm thick,

   an adjacent layer (3) made of a composite material with organic matrix reinforced by glass fibres, 30 mm thick, and

   an absorbing layer (4) of double-drawn polyethylene 2 mm thick.
8. A splinterproof lining according to Claim 5, characterised in that it comprises :

   an adhesive layer (2) made up of a first sub-layer (2a) of polyethylene approximately 15 mm thick and a second sub-layer of composite material with organic matrix approximately 10 mm thick,

   a dispersion zone (5) approximately 10 mm thick filled with polyurethane foam,

   an adjacent layer (3) of a composite material with organic matrix reinforced by glass fibres 35 mm thick, and

   an absorbing layer (4) of double-drawn polyethylene 5 mm thick.

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