EP0715145A1 - Protective device for a vehicle or a structure - Google Patents

Abstract

The system consists of at least one deployable bag (14) on the external surface of the vehicle or structure and which can be inflated by a generator in response to a detected attack. The generator can be a pyrotechnic gas generator (10) or a generator of a self-polymerising foam which inflates the bag before it solidifies. In another variant the generator is in the form of a pressurised gas container, linked to the bag through a valve. The inflatable bag is situated in a housing (6) fixed to the outer wall of the vehicle or structure by a coupling which can be dismantled e.g. from the interior of the vehicle/structure.

Description

The field of the present invention is that of protective devices for a vehicle or a structure against attack by a munition with a charged charge.

Protection devices are already known which are constituted by additional shields, called reactive shields. In a known manner, these shields comprise an explosive sheet disposed between two metal plates (see for example patent US4741244).

The impact of a charge jet formed on such a shield causes the initiation of the explosive and the projection of a metal plate against the jet.

The projected plate consumes the jet which reduces its perforating power with respect to the wall of the vehicle.

Such shields are effective, but their explosive nature imposes constraints from the point of view of security and storage. During their operation, they can also cause damage to soldiers in the vicinity of the vehicle.

In addition, their initiation causes a significant impact on the vehicle which makes them unsuitable for the protection of light or weakly armored vehicles. They are all the less adapted to this protection as their mass is high.

The initiation is caused by the impact of the charge jet formed itself, that is to say when the charge is in contact with the vehicle. It is then essential to provide for the shielding a relatively large mass of explosive to ensure the consumption of the jet, otherwise the residual effectiveness of the latter may be sufficient to cause damage to the vehicle.

Finally, the effectiveness of these shields is only ensured when the jet arrives on the armor plate with a certain incidence. Thus a jet perpendicular to a reactive armor will cross it without noticeable attenuation.

It is therefore difficult to ensure with known reactive armor protection of the roofs of vehicles against the attack of submunitions with shaped charges dispersed by vectors such as artillery shells, rockets or missiles.

There are also known, for example from patents DE2409876 and DE2507351, protective devices using nets or chains intended to initiate the charge formed at a significant distance from the vehicle.

Such devices are heavy and bulky, they must be kept deployed permanently to be effective and thus penalize the mobility and stealth of the vehicle.

It is the object of the present invention to provide a protection device for a vehicle, or a structure such as a building, which does not have such drawbacks.

The invention thus makes it possible to ensure effective protection against attacks by projectiles with a charge formed whatever the angle of incidence of these charges.

The invention also makes it possible to provide such protection to vehicles or light structures without risking inflicting damage on persons and without using detonating materials.

The invention also makes it possible to increase the effectiveness of known reactive armor, in particular against military warheads comprising several charges formed in tandem assembly (charge described for example by patent FR2552870).

Thus, the subject of the invention is a protection device for a vehicle or a structure against attack by a munition with a charged charge, device characterized in that it comprises at least one deployable bag fixed on an external wall of the vehicle or of the structure, a bag which can be inflated by means of a generator in response to the detection of an attack.

According to a first embodiment of the invention, the generator is a pyrotechnic gas generator which ensures the inflation of the bag.

According to a second embodiment of the invention, the generator is a generator of a polymerizable foam, foam which ensures the inflation of the bag before solidifying.

According to another embodiment of the invention, the generator is a reserve of a pressurized gas connected to the bag by a valve.

Advantageously, each deployable bag can be placed in a box which is fixed to the external wall of the vehicle or of the structure by a removable connection means.

Alternatively, the connecting means may be unlockable from inside the structure or the vehicle.

According to another embodiment of the invention, the deployable bag can cover reactive armor. This variant makes it possible to increase the effectiveness of reactive armor against military warheads comprising several shaped charges mounted in tandem.

The device according to the invention will include at least one threat detector which can automatically control the inflation of at least one bag.

According to practical methods of execution, the device suitable for protecting a vehicle will comprise at least one deployable bag placed on the roof of the vehicle.

It may include at least one deployable bag disposed on at least one side or front wall of the vehicle.

• la figure 1 montre en vue de profil un véhicule équipé d'un dispositif de protection selon l'invention,
• la figure 2 est une vue de dessus du véhicule de la figure 1,
• la figure 3 montre schématiquement un boîtier mis en oeuvre dans le dispositif selon l'invention,
• les figures 4a et 4b montrent le fonctionnement du dispositif de protection selon l'invention.

The invention will be better understood on reading the description of particular embodiments, description made with reference to the accompanying drawings and in which:

• FIG. 1 shows in profile view a vehicle equipped with a protection device according to the invention,
• FIG. 2 is a top view of the vehicle of FIG. 1,
• FIG. 3 schematically shows a box used in the device according to the invention,
• Figures 4a and 4b show the operation of the protection device according to the invention.

Referring to Figures 1 and 2, a vehicle 1, such as a light tracked armored vehicle, has a cassis 2 on which is mounted a turret 3. The tracks 4a, 4b are protected by side panels 5a, 5b.

This vehicle is equipped with a protection device according to the invention which comprises protective boxes 6 distributed on the roof 3a and the sides 3b, 3c of the turret, as well as on the chassis 2 and the side panels 5a, 5b.

The protection device also includes a threat detector 7 which is mounted on the roof 3a and which can for example include several radar systems having different directions of observation.

The threat detector has the function, on the one hand of detecting the approach of the ammunition with shaped charge and on the other hand of determining the direction of attack (by the roof or left side or right side, or by l 'before).

The protection device finally comprises an electronic control module (not shown) which receives the information given by the threat detector and which determines the protection box or boxes which must be actuated in response to the threat detected.

The electronic module will preferably be placed inside the vehicle and it may include a device for displaying the direction of the threat and a manual emergency command to actuate the boxes.

FIG. 3 schematically represents a box 6 fixed to a wall 8 of the vehicle.

The housing here has a substantially parallelepiped shape and it is made for example of plastic (another shape could of course be adopted for the housing, for example a cylindrical shape. It has tabs 9 which allow a removable attachment to the wall 8 , for example with screws.

The housing 6 contains a gas generator 10 of the pyrotechnic type. This generator contains a gas generating composition as well as an electric initiator igniter (not shown). The composition will be chosen among the compositions generating a large volume of gas with a limited rise in temperature, for example a composition based on sodium azide.

The igniter is connected to an electronic tripping circuit 11 by a conductor 12.

The gas generator is intended to inflate a bag 14 which is folded inside the housing 6. The bag is pinched at its edge between a flange 15 of the housing and a flange 16. The fixing of the bag and the flange on the housing can be achieved for example by gluing.

The bag is made of a material that is both flexible and resistant, for example polyamide or Kevlar, or an elastic material such as an elastomer.

The technologies relating to gas generators and air bags are well known in the field of automobile safety. We can for example refer to patent EP529371 which describes a material which can be used to make such a bag and to patents US5062367, FR2691706 and EP509655 which describe gas generators which can be used for motor vehicle safety systems.

The housing is closed by a cover 17 made of rigid plastic (for example polyvinyl chloride), its thickness is chosen so that it is broken during inflation of the bag.

It may be possible to provide a breaking point at the periphery of the cover 17 so as to facilitate its breaking.

The trigger circuit 11 has the function of causing the initiation of the gas generator in response to an order received from the control module.

In the embodiment shown here, the trigger circuit receives orders from the control module by means of an antenna 13 housed in a groove arranged in the wall of the housing 6.

In the case where the housing is metallic, the antenna will be placed outside of it.

The trigger circuit 11 will include: an energy source (such as a battery), a receiver stage, a decoding circuit, and a programmable memory in which will be placed information relating to the position of the box on the vehicle.

This information is entered when the box is mounted on the vehicle, for example by means of a switch with several positions. It allows for example to distinguish the following cases: box on the roof, box on a left side wall, box on a right side wall, box on the chassis and at the front of the vehicle.

The trigger circuit 11 will also include a computer making it possible to compare the order received by radio from the control module with the positioning information of the box which has been stored and to control or not the initiation of the gas generator.

The operation of the device according to the invention will now be described with reference to Figures 4a and 4b.

A rocket 18 flies over vehicle 1 and releases above it shaped charge submunitions 19 (for example bombs of the type described by patent FR2697079).

The threat detector 7 detects the approach of the submunitions 19 above the vehicle.

In response to this threat, he then orders the inflation of all the bags of the boxes 6 which are arranged on the upper part of the vehicle, ie on the roof of the turret and on the top of the chassis (in particular on the front and side glazings) .

Figure 4b shows the vehicle after inflating the bags in question. The volume of the bags was chosen so that, after their deployment, they occupy a volume such that the submunitions cannot come into contact with the vehicle at least at the level of the sensitive parts (turret, motorization).

The impact of a submunition on a bag will cause its initiation due to the deceleration that is caused. There will be a gas pressure giving sufficient rigidity to the bag to allow such initiation. The rigidity of conventional automotive safety bags is sufficient to perform this function.

The volume of the bags is also chosen such that, during the impact of a submunition on a bag, it is located at a distance D from the wall of the vehicle which is greater than the distance of optimal efficiency of the load (which is usually of the order of 2 to 4 calibers).

For 40mm caliber submunitions, we see that it is enough for the bags to provide a distance D greater than or equal to 160mm to significantly reduce the perforation capacity of the charges formed.

It will be noted that the impact of the impact of the submunition on the bag has no influence on the effectiveness of the protection, the initiation of the charge is ensured and at a sufficient distance from the vehicle.

The bags inflated by a pyrotechnic generator usually deploy in around thirty milliseconds (automotive technology). We therefore see that, for a submunition falling at a speed of 50 m / s, it is possible to effectively trigger the deployment of the bags when the closest submunition is less than 2 m from the vehicle. It is therefore possible to choose a threat detector with a reduced range (from 2 to 5 m), which limits its energy consumption and increases the vehicle's discretion.

In addition, the inflation is only caused when necessary, that is to say the very high probability of the vehicle being hit by a submunition (the detection of submunitions being carried out at close range).

In the event of a side or front attack of the vehicle by a missile, a rocket or a grenade, the threat detector will determine the direction of attack and the control module will then cause the bags of the boxes arranged at the front to inflate of the chassis or on the side walls considered (right or left) or possibly the inflation of all the bags to counter a missile with a roof attack capability.

For a rocket or missile flying at 300 m / s, the threat detector will need to have a range of around 50m. Detection at this distance allows an inflation time of the order of 150 milliseconds, which makes it possible to envisage bags of larger volume or bags using a specific inflation technology of the type of those which will be described below.

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

It is possible to provide a number of different bags, possibly only one if its volume is appropriate for the protection sought.

It is also possible to inflate the bags, not with a gas generator but with a generator of a polymerizable foam, for example a polyurethane foam. This foam will solidify and give the bag even greater rigidity. In addition, the foam will act as a composite "shield" and will weaken the jet, further reducing its residual perforation capacities.

Patent WO8800882 describes a foam particularly suitable for inflating deployable bags, in particular for quickly making floats.

Obviously, in this case, the performance of the detection means will be adapted to the inflation and solidification times which are greater than those encountered with gas generators.

It is possible to provide bags of different volumes or types depending on their position on the vehicle so as to adapt the protection to the part of the vehicle considered.

We can thus provide bags filled with gas to protect the roof and bags filled with foam to protect the side walls.

It is also possible to inflate the bags by means of a reserve of pressurized gas.

Connection pipes will then be provided making it possible to connect the various boxes to the gas reserve.

Each box will then include a valve, the opening of which will be controlled by a circuit for triggering the box in response to an order sent by the control module.

It would also be possible to replace the radio links between the control module and the boxes by wire links.

It is also possible to replace or associate with the threat detector carried by the vehicle another threat detector placed outside the vehicle and having a greater range, for example a surveillance radar.

It is advantageously possible to provide means for connecting the boxes and the vehicle which are unlockable from the interior of the structure or of the vehicle.

Such an arrangement allows the end of the attack to quickly rid the vehicle of the various boxes used.

We can for example ensure the fixing by means of cylindrical rods carrying a hook at their end, hooks which will cooperate with electrically controlled locks secured to the vehicle.

Springs may then be provided to facilitate the ejection of the rods and of the housings when the latches are released.

Given their volume and reduced mass, replacement boxes may be provided on board the vehicle.

It is also possible to use boxes combining an airbag with a reactive armor of known type. Such a variant will make it possible to counter military heads comprising formed charges mounted in tandem (see for example the patent FR2552870 describing such a charge). The front charge, generally of small caliber, will then be triggered remotely from the reactive armor by its contact with the bag. It will not be able to trigger the explosive of the reactive armor, which will therefore retain all its effectiveness in countering the main charge.

Concretely, for this variant it will suffice to define a housing in which the bottom is formed by reactive shielding. The airbag then covers the reactive armor providing protection to it.

The device according to the invention can obviously be used to protect fixed structures such as buildings, hangars, mobile shelters.

Claims (10)

Protective device for a vehicle (1) or a structure against attack by a shaped charge munition characterized in that it comprises at least one deployable bag (14) fixed to an external wall of the vehicle or structure, bag can be inflated by means of a generator in response to the detection of an attack. Device according to claim 1, characterized in that the generator is a pyrotechnic gas generator (10) which ensures the inflation of the bag (14). Device according to claim 1, characterized in that the generator is a generator of a polymerizable foam, foam which ensures the inflation of the bag before solidifying. Device according to claim 1, characterized in that the generator is a reserve of a pressurized gas connected to the bag by a valve. Device according to one of claims 1 to 4, characterized in that each deployable bag is arranged in a housing (6) which is fixed to the external wall of the vehicle or of the structure by a removable connection means. Device according to claim 5, characterized in that the connecting means is unlockable from the interior of the structure or of the vehicle. Device according to one of claims 1 to 6, characterized in that the deployable bag (14) covers a reactive shield. Device according to one of claims 1 to 7, characterized in that it comprises at least one threat detector (7) which can automatically control the inflation of at least one bag (14). Device according to one of claims 1 to 8 and adapted to the protection of a vehicle, characterized in that it comprises at least one deployable bag (14) disposed on the roof of the vehicle. Device according to one of claims 1 to 9 and suitable for protecting a vehicle, characterized in that it comprises at least one deployable bag (14) disposed on at least one side or front wall of the vehicle.

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