IL176947A - Reactive armour - Google Patents

Abstract

The armor has a case (2) comprising a front wall (3) and for being fixed to an external wall (4) of a vehicle. The case encloses five reactive modules (5a-5e) each comprising a metal plate (6) on which an explosive sheet (7) is applied. The plates (6) are disposed along an orientation inclined relative to a missile arrival direction (delta ). The explosive sheets are connected to an explosive layer (9) by relay explosive tabs (10), where the layer is integrated to the front wall.

Description

Reactive armour Giat Industries C. 168494 The technical scope of the invention is that of reactive armour. ' < Reactive armour is well known to the someone skilled in the art, for example by patent EP161390. It implements at least one sheet of explosive which is placed in contact with a metallic plate or between two metallic plates, this being thereafter installed into a case fastened to a vehicle.

When the jet of a shaped charge impacts the external wall of the case, the sheet of explosive is ignited by the shock and it projects a plate towards the jet. This projected plate consumes the shaped charge jet which thereafter does not retain enough energy to perforate the vehicle's body.

Know reactive armour is effective against shaped charge projectiles but its effectiveness against kinetic energy projectiles (or APFSDS projectiles) is lower.

Indeed, the latter are presently of substantial length (L/D > 10) thereby ensuring perforating effectiveness even on armour provided with reactive protection.

The aim of the invention is to propose improved reactive armour having, in a reduced volume, increased effectiveness against kinetic projectiles.

Thus, the invention relates to reactive armour incorporating at least one metallic plate positioned in a case comprising a front wall intended to be perforated by a projectile, such metallic plate able to be projected further to the ignition of at least one sheet of explosive applied to the"' plate, such reactive armour wherein it incorporates at least two projectable metallic plates, sheets of explosive applied to the plates all of which are connected to an ignition device integral with the front plate.

The ignition device may advantageously incorporate at least .one layer of explosive integral with the front wall and connected to the different sheets by explosive transmission means .

According to one variant, the ignition device may incorporate at least one layer of explosive integral with a side wall of the case.

The projectable plates may be substantially parallel to one another. < The plates may be separated from one another by the same distance .

The armour may incorporate at least■ three parallel plates .

The plates may form an angle with respect to a direction likely to be positioned substantially horizontally.

The plates may be arranged so as to be projected in the ■ direction of a lower part of the case or else, alternatively, arranged so as to be projected in the direction of an upper part of the case.

The invention will become more apparent from the following description of a particular embodiment, such description being made with reference to the appended drawings, in which: - Figure 1 is a transversal cross section of reactive armour according to the invention, - Figure 2 is a top view of this reactive armour, the case being sectioned along plane AA in Figure 1, Figures 3a, 3b, 3c, 3d, 3e and 3f are schematic views showing different operating stages of the armour according to the invention.

With reference to Figures 1 and 2, reactive armour 1 according to the invention comprises a case 2 incorporating a front wall 3. The case 2 is intended to be fastened to an external wall 4 of a vehicle (not shown) . Fastening will be made by appropriate means such as lugs or flanges which are not shown here.

The case 2 encloses several reactive modules 5 (here five modules: 5a, 5b, 5c, 5d and 5e) .

Each reactive module comprises a single metallic plate 6 onto which a sheet of explosive 7 is applied. Classically, each sheet 7 is bonded to the plate 6 in question.

According to an essential characteristic of the invention, the metallic plates 6 are arranged at an inclination with respect to a direction δ which is the oncoming direction of the threat (projectile) that the armour is intended to counter. This direction is substantially horizontal. Thus, each plate 6 forms an angle a with respect to the direction δ which here is perpendicular to the wall 3. This angle a is of between 5° and 45°.

All the plates 6 are parallel to each other and are spaced at a distance d which depends on the threat and definition of the reactive modules 5. This distance may be of between 20 mm and 150 mm.

The plates are fastened to the case 2 by appropriate means, here for example by welded brackets 8.

The different sheets of explosive 7 are connected to an ignition device which is integral with the front wall 3. This ignition device here incorporates a layer of explosive 9 which is bonded to the front wall 3 and which is connected to the different sheets 7 by explosive transmission means, for example bonded explosive booster tabs 10.

The explosives constituting the sheets 7, layer 9 and the booster tabs 10 may differ according to the characteristics required (detonation speed, sensitivity) .

The front wall 3 here does not play an armouring role. It may thus be of thin sheet steel or else be made of a light material such as an aluminium alloy. The plates 6 are made of a metallic material, for example armouring steel.

The reactive armour according to the invention will preferably be arranged such that direction δ is substantially horizontal. Moreover, the sheets of explosive 7 will be arranged above the plates 6. Thus, the plates 6 are projected downwards (B) when the armour is ignited. The orientation of the armour 1 is indicated in Figure 1 by letters H (high) and B (low) .

The functioning of the armour will now be described with reference to Figures 3a to 3f.

The outline of the case 2 is not shown on these Figures, nor are the fastening means 8 for the modules 5.

Figure 3a shows the armour 1 at the moment of impact of an APFSDS projectile 11 on the front wall 3.

Whatever the projectile's point of impact, the shock will cause the ignition of the explosive layer 9 (Figure 3b) .

Detonation speeds in explosive materials are of around 6,000 to 8,000 m/s. Thus, well below one millisecond after the impact, the layer of explosive 9 will have transmitted the detonation to all the tabs 10 (Figure 3c) . These will practically simultaneously ignite the sheets of explosive 7 which will ensure the projection of all the plates 6 (Figure 3d) . Each plate is projected at a velocity Vp of around a few hundreds of metres per seconds.

Thus, whereas the projectile 11 continues its passage through the armour case, it receives the impacts of several plates hitting it successively and at an incidence approximating angle a.

These repeated shocks cause the projectile 11 to fragment into several pieces (11a, lib, 11c, lid) which are also strongly deviated leaving them with a very reduced perforating capability (Figures 3e and 3f ) .

With respect to known armour, here not only the consumption of part of the projectile's 11 energy is ensured but the impacts on it are multiplied thanks to the structure associating several parallel reactive modules. Thus the pieces of projectile are sheared and destabilised through the projectile being successively impacted from different directions across its axis.

Someone skilled in the art will easily be able to parameter the armour according to the invention according to the 'characteristics of the projectile to be countered. The number of reactive modules 5 may thus be varied, as may the value of angle a and the distances d between each module 5.

Different angles a may also be adopted for each module and different distances d may be provided between the plates 6 of the modules.

The description demonstrates that the armour is all the more effective in that impact with the projectile occurs at its lower part. Indeed, the lower the impact, the greater the number of plates coming to impact the projectile.

It is therefore pointless to produce armour according to the invention which incorporates too large a number of modules. It will be preferable for several armours according to the invention to be placed in juxtaposition each incorporating between 3 and 6 modules. ■ Different variants are possible without departing from the scope of the invention.

It is thus possible for the modules to be oriented in the opposite direction (explosives 7 positioned below the plates 6 thus plates 6 projected upwards H) . Such an arrangement will enable a reduction in the impacts received by the vehicle. The reactive armour has been described with a vertical front wall 3 perpendicular to the on-coming direction δ of the threat 11. It is naturally possible for a front wall to be provided that is inclined with respect to direction δ.

When integrating the armour onto a vehicle, the armour should be oriented such that the reactive modules are inclined with respect to the direction of attack δ (in principle, horizontal) . It is thus quite possible for reactive armour to be defined in which the reactive modules 5 are perpendicular to the frontal wall 3 of the case. In this case, the case (and thus the modules) merely needs to be inclined with respect to a horizontal plane when being mounted.

It- is also possible for armour to be defined according to the invention in which the reactive modules are arranged in parallel planes to one another but not parallel to a horizontal plane. Someone skilled in the art will select the spatial orientation of the reactive modules according both to the threat to be countered and to the constraints of their integration onto a vehicle.

It is lastly possible for an ignition device to be designed incorporating at least one layer of explosive integral with a side wall of the case. This layer will be provided in addition to the layer integral with the front wall and will be connected to the latter (as well as to the reactive modules) by pyrotechnic transmission means. Such a variant will enable threats to be countered which approach the armour from a direction which does not cross the front wall .

Claims (9)

1. . Reactive armour (1) incorporating at least one metallic plate (6) positioned in a case (2) comprising a front wall (3) intended to be perforated by a projectile, such metallic plate able to be projected further to the ignition of at least one sheet of explosive (7) applied to the plate (6), reactive armour wherein it incorporates at least two projectable metallic plates (6), sheets of explosive (7) carried by the plates all of which are connected to an ignition device (9) integral with the front plate (3) .

2. . Reactive armour according to Claim 1, wherein the ignition device incorporates at least one layer (9) of explosive integral with the front wall (3) and connected to the different sheets (7) by explosive transmission means (10).

3. . Reactive armour according to Claim 2, wherein the ignition device incorporates at least one layer of explosive integral with a side wall of the case.

4. . Reactive armour according to one of Claims 1 to 3, wherein the projectable plates (6) are substantially parallel to one another.

5. . ' Reactive armour according to one of Claims 1 to 4, wherein the plates (6) are separated from one another by the same distance (d) .

6. . Reactive armour according to one of Claims 1 to 5, wherein it incorporates at least three parallel plates (6).

7. . Reactive armour according to one of Claims 1 to 6, wherein the plates' (6) form an angle (a) with respect to a direction (δ) likely to be positioned substantially horizontally .

8. . Reactive armour according to Claim 7, wherein the plates (6) are arranged so as to be projected in the direction of a lower part (B) of the case (2).

9. . Reactive armour according to Claim 7, wherein the plates (6) are arranged so as to be projected in the direction of an upper part (H) of the case (2) . For the Applicants REMOLD COHM AND PARTNERS Byo