NO338962B1 - Reactive protective device - Google Patents

Abstract

The invention describes a rigid or flexible pyrotechnic protection surface which is free or integrated into a housing, for medium-heavily and lightly armored vehicles, protection arrangements and surfaces to be protected, corresponding to FIG. 1 , with a single-layer or multi-layer carrier ( 4 ) of any configuration which is inclined in the region of action of the threat and pyrotechnic layers ( 2, 3 ) mounted on the carrier on both sides. Shock waves and reaction gases are formed by the firing of both layers and are accelerated both in opposite relationship to and also in the direction of the penetrating hollow charge threat ( 1 ). In that way both the front powerful blast elements and also a great blast length are disrupted and thus lose their penetration capability or are at least greatly diminished in respect of their residual power. The pyrotechnic protection surface is disposed in a condition of dynamic equilibrium over the entire period of action. No influences which are destructive or relevant in terms of terminal ballistics are exerted on the external region or on the structure to be protected. To increase the overall effect selected explosive surfaces are covered on the inside and/or outside with non-metallic materials which do not form ballistic fragments so that they are set in motion at different speeds upon being blasted with a hollow charge. For practical use it is particularly advantageous if the wall of the housing is incorporated as one or more of the inert materials into the structure of the armoring arrangement. The combination of inert and pyrotechnic materials which are operative to afford protection, in conjunction with a suitable layering arrangement, means that the response time can be reduced in relation to known armoring arrangements to such an extent that only a very small part of the hollow charge blast can still penetrate the armoring. With such arrangements, the weight in relation to surface area which is necessary to afford protection can be markedly reduced in comparison with known reactive armoring arrangements without requiring a high-mass disruption layer which flies towards the vehicle. In that way only comparatively light structures are required on the vehicle side in contrast to known reactive protection systems.

Description

The invention relates to a pyrotechnic protection, more specifically a splinter-free reactive protection device against hollow charge threats.

Anti-tank handguns with hollow-charge warheads, due to their high penetration effect, represent a major threat, especially for light to medium-heavy armored vehicles. In particular, the Russian PG 7 in Out of Area operations has proven to be a threat that must be taken into account, as this weapon system is widespread all over the world.

A protection of light and also medium-heavy armored vehicles against such anti-tank handguns is only limited or not at all possible with the usual reactive and special passive protection systems. This is because the vessel's weight is limited and the surface weight of the armor required for protection is too high. Lighter vehicles have only thin walls, as the vehicle protection is usually only sized for small-caliber armor-piercing ammunition of caliber up to 14.5 mm. Various reactive, i.e. protective systems that work with explosives have therefore been developed, in order to be able to reduce the surface weight required for protection in that way.

For example, an HL protection of medium armored vehicles with a basic protection of approximately 30-50 mm armor steel equivalent using passive protection systems requires an additional surface weight of the order of 500 kg/m<2>, and the previously known, already effective reactive protection systems require a extra surface weight in the order of 300 kg/m 2 in order to be able to meet the threats from the aforementioned anti-tank weapons.

Since the beginning of the 1970s, devices have been known which have been developed both against the threat from hollow charges (HL threat) as well as against weight projectiles. With these devices, pyrotechnically accelerated elements will cause a lateral disruption of the incoming or penetrating or penetrating threat, so that the knock-on effect is reduced. When initiated by the incoming threat, such devices are termed reactive protection. If they have controlled ignition, the devices are referred to as active armour. Reactive devices predominantly involve a one- or multi-layer, one-sided or two-sided coating of the explosive with, as a rule, metallic plates. Such devices are used everywhere for many armored vehicles, with dimensioning both with respect to hollow charges as well as weight shells.

Reactive systems that accelerate plates have the decisive disadvantage that more or less large masses have to be accelerated up to speeds of several hundred meters per second, which not only burdens the environment, but also the supporting structure. Therefore, reactive armor is mostly made as modules (flat elements) in box construction form. When it comes to objects that only require light protection or when it comes to thinner structures, the effort of reactive components is severely limited, or not possible, precisely as a result of the load to which the system itself is exposed. This applies particularly to devices against weight grenade threats, as the reduction in effect requires an acceleration of relatively large masses. In the case of reactive devices against hollow charges, the required disturbance masses are admittedly considerably smaller, but in return they require much higher speeds for the achievement of laterally acting disturbance masses compared to those with speeds of up to 10 km/sec. Incoming hole charge beams.

There are also known devices where the hollow charge beams are disturbed during penetration, directly by means of an explosive layer or by means of electric fields, the hollow charge beams being deflected and thus a reduction in effect is achieved. Such devices are, when explosives are used, associated with the use of significant thicknesses of explosives, so that over a longer period of time (depending on the beam length to be disrupted) beam-disturbing conditions are maintained. The explosive layer certainly ignites quickly upon penetration by hollow charge beams, but with normal sandwich devices will not produce any directed lateral beam disturbance, especially in the front area, even at a greater slant angle in relation to the penetrating beam. Such an effect is only achieved when there is an inclined, quasi-explosive-free surface, which is possibly combined with a protective (damping) wall. Clean, relatively thick cutting or explosive layers or explosive foils laid on a plate or a wall are found in several known applications. This basically concerns reactive devices with a standard design and with one-sided explosive coating.

Although the detonation of the explosive occurs quickly in hollow charges, a certain time is still necessary for the build-up of a pressure field, because the struck target material is initially accelerated mechanically and roughly hemispherically away from the penetrating beam tip. Thereby a cavity is created, where a more or less larger part of the particularly effective, very fast jet tip area can pass without obstruction. However, this area is decisive for the residual effect of the HL threat and thus determines the degree of effectiveness of the protection, respectively the resource use necessary for a reduction of the effect.

Similar considerations apply to coating the explosive layer with plates that are to be accelerated. The plates must not only be accelerated under the influence of shock waves and gas forces, but must also be able to span the crater formed by the jet tip, in order to quickly hit the jet laterally. The structure of the device, and especially its angle in relation to the penetrating threat, will be the determining parameters here. With the help of several layers and partially highly inclined reactive protections, several known designs have attempted to minimize the disadvantages described above as a result of the formation of craters. As a rule, however, this has led to a build-up with a lot of explosives or to modules with a small effective protective surface and a large depth in relation to the surface covered. Furthermore, this results in negative edge influences and insufficient overlaps. In addition, the proportion of constructively conditioned dead masses is increased. Such masses, which do not participate directly in the protection, above all in the case of previously known reactive protection devices constitute a significant proportion of the required surface mass and reduce the effectiveness of the protection accordingly.

Reactive protective devices are also known, which are arranged in front of the structure to be protected, with the aim of being able to reduce the negative mechanical or end-ballistic effects on the surroundings by means of suitable explosive coatings. Such, usually multi-layered and usually also complex designs, have a course of action for the individual components and their interaction that is difficult to determine. It has indeed proven to be effective against hollow charges, but initially they are subject to the limitations of effectiveness and assessment criteria described above.

Hitherto known effective and reactive protection systems also cannot provide complete protection against a HL threat, even when using significant surface masses, because only a certain proportion of the hole charge beam is affected by the disturbance measures. Thus, approximately 20 to 30 percent of the hollow charge ammunition's effect must be compensated as residual effect with the vehicle's basic armour.

The weight advantages that reactive devices have, compared to passive protection devices, are offset by several disadvantages. Thus, conventional reactive protection systems work predominantly by exploiting the principle of flying plates, which firstly represent a clear danger to the environment around the armored vehicle, and secondly affect the structure with the plate flying against the vehicle wall. This is particularly important for lightly armored vehicles.

Several such armors are known. The accelerated plates preferably consist of steel, for example as described in EP 0 379 080 A2. There, the reactive protection is combined with an additional passive protection, thereby compensating for the part of the hole charge beam that is not sufficiently reduced by means of the reactive protection.

IUS-A-5,824,951 describes a reactive armour, where the inert plates surrounding the explosive consist of different materials. The plate accelerated towards the hole charge beam is made of glass, and the plate hurled towards the vehicle by the beam is made of steel. Behind it, together with the beam flying plate, there is a cavity, so as not to interfere with its movement in time with the interaction with the hole charge beam.

In US-A-4,741,244 a reactive armor is described, where behind the vehicle flying plate there is a cavity. In this publication, it is said that the protective effect of the rear plate is greater than the beam-moving plate. The rearward flying plate of steel moves at a very high speed, so that the vehicle must be equipped with a correspondingly strong base protection, so that the vehicle's wall is not penetrated by parts of the reactive protection.

EP 0689028 A describes a reactive armor element effective. The element is a multi-layer composite body in which each layer seals against each adjacent layer, the multi-layer composite body comprises an outer cover, at least one explosive layer, at least one intermediate inert body and a base plate.

In DE 37 29 211 Cl, a reactive protection is described, where obliquely arranged sandwich structures in the direction of the vehicle are combined with a layered build-up of explosives and brittle materials, such as glass for example. The build-up must act against the front part of the hole charge beam, which due to the inertia of the inert plates penetrates almost unhindered through the stored reactive protection. In the device described, the parts that hit the vehicle will exert a large load.

In DE 199 56 297 C2, a reactive protection against hollow charges is described, where obliquely arranged explosive layers on the side of the shot are coated with a disruptive layer of fiber composite material in order to avoid hard splinters. At least one disruptive layer is of a high-strength fiber composite material, in the form of a textile raft structure of artificial or growing raw materials or combinations thereof.

DE 199 56 197 A describes a classic reactive armour, where the usual metallic component is simply replaced with a non-metallic plate (preferably of fiber composite material) to avoid structural and environmental damage. The protection against HL and weight grenade threats is achieved with an acceleration of one or more such plates, the reactive device being arranged in a non-metallic housing. The mentioned function of an extra, such as bulge plate designated plate, is not realizable.

US-A-5,637,824 describes a classic reactive composite armor with an explosive layer and a metallic plate accelerated in the direction of the threat. As a result of the detonation, the effect of the HL beam is reduced by the beam being disrupted by a relatively thick and dynamically acting layer arranged behind the explosive layer and blocked backwards by means of a metallic plate. The dynamic effect of the intermediate layer can be enhanced by means of a layer or layer placed in the zone of action and by means of a further explosive layer in front of the rear metallic plate. The device is based on the effect described in the literature of a so-called "crater collapse" (Dynamic Collapse Effect). As materials for the provision of this effect, practically all liquid, metallic or non-metallic materials are mentioned, most of which will not produce such a physical effect. A case is also described where the front dam only consists of a non-metallic protective layer, so that an increased explosive thickness is required to provide the internal pressure necessary for a dynamic effect. After the detonation of the first foil, there will be a normal reactive armor with an explosive layer coated on both sides. In addition, not only the environment, but also the structure in particular is stressed.

DE 37 29 211 C concerns a classic reactive sandwich device (metallic plate with an explosive intermediate layer) which is embedded in hair foam in a special way. This first effective layer is followed by an explosives layer with a subsequent brittle body structure (glass body) with a separating layer of explosives. The entire complex device is housed in a metallic housing. Basically, the device described there therefore represents a relatively thick armor with diagonally inserted reactive sandwiches of explosively accelerated steel plates, the spaces being filled with hair foam. The effective beam tips, which travel practically unhindered through such devices, are to be intercepted in the secondary layer which consists of a dynamic vitreous body structure.

Also in WO-A-94/20811, it concerns a conventional reactive device with two mutually inclined layers of explosives coated on both sides in a massive metallic housing. The inventive object is not the classic and reactive sandwich arrangement with metallically accelerated plates, as is well known, but how they are arranged in a massive housing. With the structure, protection is to be achieved not only against HL, but also against weight grenade threats. Such structures are used in several armored vehicles of Soviet origin.

A fundamental problem with the reactive sandwich protection devices, especially against weight grenade threats, consists in the initiability of the explosives used at relatively thick coating thicknesses, which thin coating thicknesses are necessary for the required low energy density as a result of shock loads on the protection/housing structures. The device described in DE 33 13 208 C therefore aims, by means of a porous or foamed layer inserted in a normal reactive armouring, with inserted explosive components, to provide a beam magnification which can be compared to that achieved with the so-called crater collapse. This layer is, especially for protection against weight grenade threats, coated on both sides with metallic plates and thus represents a reactive sandwich of the usual type.

DE 102 50 132 A describes protective devices against mines which provide shock waves and deliver projectiles, and it does not concern hollow charges. The protective effect occurs by means of containers with a filler consisting of a liquid and/or a flowable medium. Basically, it is about an admittedly dynamic protection structure, but not about a reactive device as protection against HL threats.

Based on the previously outlined embodiments regarding the known technique within reactive protection systems, it can be deduced that the hitherto known reactive systems are still relatively heavy and require a relatively high basic protection to compensate for the residual effect. In the case of anti-tank handguns, this means a necessary basic protection in the order of 60 to 80 mm armor steel equivalent.

The problem underlying the invention is to be able to protect also medium-heavy and also only lightly armored vehicles against hollow charges and with the use of a correspondingly small base protection, with the particular aim being to achieve protection against medium-caliber hollow charge projectiles, such as PG- 7, without the risk of additional, ballistic-acting splinters occurring. Such HL protection for lightly armored vehicles requires: a very high efficiency of the protection device, a low surface weight with

at the same time minimal residual effect,

- the vehicle wall must not be impacted too strongly or penetrated by parts of the protection system, - the vehicle's surroundings must not be burdened with splinters as a result of the protection system, - the vehicle's mobility must not be restricted, and possibly parts of the protection system must be able to be removed or put in place during the effort,

the respective road traffic regulations (for example in Germany: StVZO) must

satisfied,

there must not be an extended danger beyond the protection system as a result of the explosives on the vehicle, i.e. in Germany, for example, you must have a classification 1.4 in accordance with the GGVS (Gefahrgutverordnung),

if protection is fitted, it must be possible to quickly access the covers and stowage space.

According to the present invention, this purpose is achieved by arranging at least two layers of a pyrotechnic material with the same or different quantity ratios and/or thicknesses at a distance from each other, free or in a housing of a non-metallic material, such as for example rubber, and an angle in relation to the direction of protection. Advantageous designs and further developments of the invention are indicated in the independent patent claims.

In a preferred embodiment, this pyrotechnic protection structure consists of a support inclined in the threat's hit/effect area with an arbitrary shape, where pyrotechnic layers are placed on both sides. Upon ignition of both layers, shock waves and reaction gases are formed, and the layers are accelerated towards as well as in the direction of the penetrating threat. Thereby, in the case of hollow charges, not only the front, effective beam elements, but also a crucial part of the entire beam length will be disrupted, so that the reverberation effect is lost. During the entire period of effect, the pyrotechnic structure will be at least approximately in a dynamic equilibrium and will not exert any ballistically relevant or destructive influences on the surroundings, i.e. neither in the outer area nor on the structure itself to be protected. The size of the required area will be found using simple kinematic considerations of the penetration process.

It is about an imaginable simple and principled arrangement, which basically has no limits or restrictive technical provisions. This provides a height of innovation, which has not been reached so far with known reactive devices. Moreover, the pyrotechnic protection surface is suitable to provide a strong increase in the level of protection for a number of known armours, both as pre-connection as well as integration.

Basically, pyrotechnic protection surfaces can be easily combined with devices against weight grenade threats. In any case, protection optimizations against multiple threat types will require no or only small dead masses.

Of course, despite the initially unlimited design possibilities, one must ensure a sensible relationship between the few participating parameters. In the case of ordinary reactive armours, the effect will depend to a decisive extent on the dimensioning. In the present invention, it is therefore initially only necessary to take into account a few assumptions, which also apply to all reactive devices. This includes the minimum explosive thickness to ensure an initiation or a through detonation. An exception is the desired deflagration, to the extent that this is not to be achieved by means of the composition of the pyrotechnic layers. Further prerequisites will arise from the geometrical conditions and from the relationship between threat and protective surface dimensioning. Here one must take into account the materials used, such as, for example, the type of explosive or admixtures and the number of protection surfaces.

As a result of the great effect, the mass of explosives used per unit area can be significantly smaller for a pyrotechnic protective surface according to the invention, compared to the previously known reactive armours. This may involve reductions of up to 50%, when the aforementioned limitations are taken into account. As a starting point for the design, it can be assumed that the thickness of the explosive coating at an angle between the protection area and the threat of more than 30° can amount to approximately 50% of the average beam diameter.

Principal considerations regarding the achievable velocities v for free and coated explosive surfaces can be carried out using a Gurney equation for planar pyrotechnic surfaces:

where a = Mx/C and b = M2/C as well as A = (1 + 2 a)/(l + 2 b),

M/C: ratio between mass of wall and explosive,

Index 1: anterior surface, index 2: posterior surface,

(2 E)0'5: Gurney factor (here assumed to be 2,800 m/sec.),

V2= Breeding

In the case of quasi one-sided coating, a or b will be equal to zero.

In the table below, some dimensions have been calculated, which emphasize the principle considerations. Absolute values are not important here, but the clear confirmations of the considerations in the context of the present invention (D: thickness, M: mass, S: sandwich).

With larger explosive material thicknesses (DC) and relatively thin carrier layers, speeds in the order of the gas velocity of up to more than 4 km/sec are theoretically achieved. The free surface, or a weak coating of explosives on the surface, determines via an approximation the theoretically achievable velocities.

With very thin coatings (foil surface) in the order of 0.1 mm, very high surface velocities (over 3 km/sec.) will also be achieved with very small explosive foil thicknesses (for example 2 mm - the minimum thickness is determined by the ignition properties). Already with still very weak coatings (for example 1 mm Al) the surface speed will drop to below 2 km/sec. Compared to normal sandwiches, the surface speed is still quite high.

With one-sided or quasi-one-sided coating, a medium explosive material/thickness and a relatively massive wall (for example for weight grenade protection or for system reasons), with realistic dimensioning and a very high one-sided speed, wall velocities in the order of only 50 m/sec will be achieved. Such low speeds can still be controlled using mechanical means. For this border area of the designs according to the invention, particularly interesting combinations are therefore made possible, where a high degree of protection efficiency can be combined with a minimum building depth, without straining the surroundings and the structure.

The following principle devices are considered in connection with designs of the carrier in accordance with the present invention (see figures 4 and 5): Figure 4A: Symmetrical coating with pure explosive foils. This naturally also includes foils with surface treatment or surface protection. Thereby a simultaneous detonation is achieved in a first approximation. The "dynamic containment" using the detonation gases will increase the effective containment mass, and a maximum surface velocity in the order of the gas velocity is achieved. By definition, the wall itself will not be subjected to an acceleration. The speed of the reaction gases can be significantly influenced by the foil design and the explosive used, and substances brought into the explosive matrix can also play a role here. If the explosive substance layer is coated with a massive layer, as is the case predominantly with classic sandwich designs, this possibility of influence will be greatly reduced. Figure 4B and 4C: Different explosive coatings. In this way, a resulting speed is achieved for the partition, respectively the carrier. With a corresponding design and a suitable choice of material, this basically means no restriction of the insert band width. An almost complete symmetry in the entire reactive device can be achieved with a symmetrical device of two surfaces. As an estimate for a rough calculation of the resulting acceleration to the bearing layer, respectively the connecting layer, either in the direction of the threat or against the threat, one can, in a first approximation, use the difference thickness between the two explosive foils. Figure 5A: Between the pure explosive foils there is an extended wall (for example with a very low density of the order of 0.1 g/cm ). Even with high compressibility, this wall can be dynamically relatively hard. Figures 5B and 5C: The explosive foils with the design shown in Figure 5A are coated with a very thin layer, either on the wall side (carrier side) or on the outside (threat and object side). In this way, with the previously stated Gurney consideration, it is possible to set the desired gas expansion rate on this side. In this way, for example, even in the area with less surface coverage, an extension of the effective time against the threat can be achieved.

Of course, the explosive foils or the coatings can have variable thicknesses. Thereby, for example, the effectiveness of a partial surface, for example for compensation of different protection depths or settings, can be affected.

In connection with the interception of the fast jet parts with sufficiently high speeds for the free foil surfaces, it can be provided with suitable surface coatings

very broad-acting devices with a high overall efficiency. A one-sided movement of the explosive foil with an accelerated plate with classical dimensioning can be considered a borderline case. However, this only applies to these sub-components in a reactive structure and not to a reactive device according to the invention.

A thicker, supporting layer or a separating layer between the explosive foils and with additional physical properties, for example in connection with the dynamic behavior or special properties against shock waves, can be advantageous because the penetration depth can thereby be increased, i.e. more beam particles, respectively a greater beam length will then remain in engagement. Known explosive dynamically compressed vitreous will also work on this basis. However, they will be relatively heavy, not least because of the required thicknesses in the mass balance of an armour.

In the case of reactive armour, the effect of the element size on the containment, and thereby on the speeds achievable by the accelerated components, is of great importance. It is easily realized that small element sizes and larger explosive thicknesses, as well as larger element masses, will have a velocity-reducing effect. This is because the speed of an element with a small surface is also reduced more the thicker (rich in mass) the coating and the thicker the explosive layer. This speed reduction can be in the order of 50%, so that it can thus largely override the influence of other target-specific parameters. In the case of very small moving masses, or in the case of pure explosives layers, the influence of the element sizes is correspondingly smaller. In a first approximation, there will be no influence on the velocity of the gas cloud. This entails a further advantage of devices according to the invention. In particular, the very important dimensioning criteria, such as module size and effect in the edge zones, are affected in a positive way.

With a multi-layer construction of the carrier, this can also be used as a control element for the energy and signal transfer between the explosive foils. A dimensioning criterion here will be the acoustic impedance of the materials used.

The explosive layers used for pyrotechnic protection surfaces according to the invention make only small demands on production tolerances and surface quality and thus on the production methods. This significantly increases the possibilities one has for designing the surface of a protective element.

Another improvement is achieved with the method known in principle, i.e. the coating of the surfaces of the pyrotechnic layers with materials of different densities. It is advantageously used for coating materials which have a lower or higher density, which are brittle, which split or delaminate, such as glass, composite materials, ceramic materials or shock-resistant, but at relatively low deformation rates, soft materials, such as rubber, whose high inertia after a relatively long reaction time will spread or erode the middle and rear part of the hole charge beam over a longer period of time. Metallic or non-metallic foams are suitable as materials with low density, for example. In the case of free explosive surfaces, air as the surrounding medium will, as a result of its lower inertia in a short reaction time and very high acceleration, disperse the fast parts from the front area of the hollow charge beam.

With the help of the model rules used in ballistics, in particular Cranz's model law, which was originally formulated for the detonation of explosives and has later been extended to apply to the entire final ballistics, geometric changes can be made within wide limits. In this way, a design tested in practice can be transferred to comparable applications, within very wide limits, by means of physical and geometrical design regulations. Further aids for the dimensioning will be numerical simulations.

The high efficiency of a device according to the invention is basically not tied to a house. Containers, housings or covers primarily serve to fix or protect the effective layers, also in connection with combined protective components and against external influences.

In practice, it would be advantageous to link the mode of action of the protective device according to the invention together with constructive provisions for the object to be protected. This may involve a simple summation and also additional protection structures. The inert materials on the front and/or back of the house, which materials consist of one or more layers, can also be optimized with regard to improving the effect against weight grenades.

In a preferred embodiment, the layers of explosives and inert materials will be brought into pre-provided pockets in the protection module, thereby enabling a simple and production-adapted adaptation of the reactive protection to the vehicle to be protected.

The drawings and descriptions of the conditions in case of incoming and penetrating threats are indicated in the list below: Figure 1 Principle structure of a pyrotechnic protection surface according to the invention. Figure 2 The operation of the pyrotechnic protection surface in Figure 1 on a relative basis

early time during penetration and penetration.

Figure 3 The operation of the pyrotechnic protection surface in Figure 1 at a later date

time during penetration and penetration.

Figure 4 Examples of pyrotechnic protection surfaces as in Figure 1, with thin carriers. Figure 5 Examples of pyrotechnic protection surfaces as in Figure 1, with extended

carriers.

Figure 6 Example of a pyrotechnic device with two free explosive layers.

Figure 7 Example of a pyrotechnic device with internal containment.

Figure 8 A further example of a pyrotechnic device with a hoop sandwich.

Figure 9 Example of a pyrotechnic device with container/housing.

Figure 10 A further example of a pyrotechnic device with container/housing.

Figure 11 A further example of a pyrotechnic device with container/housing.

The aforementioned and other features and advantages of the invention will emerge from the following description of preferred examples, with reference to the drawing. In the drawing, Figure 1 shows the principle structure of a pyrotechnic protection surface according to the invention, with an implied incoming hole charge beam, respectively threat 1, the pyrotechnic coatings 2 and 3 and the intermediate carrier 4.

Figure 2 shows the condition and the way the pyrotechnic protection surfaces in Figure 1 work, at a relatively early stage during penetration and penetration. The initiation (ignition) of the forward (facing the threat) pyrotechnic coating 2 occurs where 1 hits 2 (small circle 5). The detonation front expands in 2 at a rate of the order of magnitude of the average beam penetration velocity in the part of the hole charge beam to be averted (symbolized by arrow 6). If it is a relatively thin carrier, then the rear pyrotechnic coating 3 will be initiated, not only as a result of the hemispherical shock waves emanating from 5, but also as a result of the beam tip penetrating at the point where 1 hits 3 (smaller circle 5A ). For the propagation of the detonation front in 3, the same conditions apply as in 2 (arrow 6A). As a result of the geometrical conditions, and in particular also as a result of the design of 4, an asymmetry can form in the control room (large circle 7) applicable at the considered time for the force unfolding and thus for the overall dynamics. However, this will only have a small influence on the basic properties of the described device. The detonation fronts that spread towards the threat as a result of accelerated reaction gases (and possibly accelerated surface layers) are symbolized by the expanding pressure field 9.

In the case of free or only slightly coated surfaces of 2 and 3, high propagation velocities occur for the detonation front and the reaction gases in the direction of the penetrating/penetrating beam (arrow field 8). The speed is also increased quite decisively as a result of the containment property of the surfaces 4 and 3 (before ignition static as a result of slow mass, after the ignition of 3 as a result of the pressure fields that form) towards the explosive layer 2. As a result, beam parts will be loaded laterally in the tip area, so that the beam parts are deflected or destroyed. In the case of the hole charge particles, which are particularly sensitive to disturbances in the tip area, impacts with low energy will be sufficient to achieve a large reduction in effect (destruction) of these parts.

The front beam parts will, as a result of the penetration mechanism described above, penetrate the front pyrotechnic layer 2. They are captured in the rear pyrotechnic coating 3. As a result of the current physical conditions, the geometrical conditions and the resulting velocities in in connection with the short reaction times, the front beam tip will also be affected in the rear zone, so that overall a complete loading, deflection and thus destruction of a large part of the hole charge beam, also of the front particles, is achieved.

These conditions are illustrated in figure 3. Part of the pyrotechnic coating 2 has already been converted into a pressure field 9A which spreads. The control room for the total dynamics symbolized by the large circle 8A, with arrow fields 8 and 9 for the reaction surfaces of 2 and 3, shows both a well-balanced overall picture of the forces as well as the load on the front beam tip in the area indicated by a smaller circle 11 to the disturbance field 12 formed by 3. Figure 4 shows examples of symmetrical or asymmetrical pyrotechnic protection surfaces with intermediate carriers. These can be designed to be protection-relevant (for example as weight grenade protection or as protection against flat cone charges) or be extremely easily made. Corresponding reactive devices can also be formed by a single (flat or curved or arbitrarily designed) element or by means of a combination of two or more elements that are put together to form a surface. In this way, it will be possible to adapt the reactive protection according to the invention to the threat that is assumed to exist. Figure 5 shows some examples of (here symmetrically arranged) pyrotechnic protection surfaces with extended carriers or inner surfaces (4A, 4B, 4C). These can, as described, consist of extremely light materials or can simultaneously serve as inner volumes (for example as containers) for other purposes. Of course, the design of these internal areas in and of itself is not subject to any limitations, as long as the operation of the reactive components is not thereby restricted in an undesirable manner.

As design examples (see figures 6 to 11) and conducted tests show, a one-sided and/or two-sided coating of the explosive surfaces in the inner area and/or outer area (13, 13 A, 14, 14A) will be of great importance, especially for the overall efficiency of a armour, and likewise also of great importance for the distribution of the still necessary protection against the threat's residual penetration depth.

In order to achieve an optimal protective effect for reactive devices according to the invention, the one- or two-sided containment of one of the explosive layers can be advantageous for the overall balance of the protective effect or in connection with design technical requirements. Such containment of the explosive to increase the overall protective effect takes place advantageously with masses that dissolve, such as, for example, surfaces of metallic or non-metallic foils, GRP, ceramics or glass or also liquids and gels.

In accordance with what has been mentioned above, the damming materials are advantageously selected in such a way with respect to quantity and density that, in combination with the pyrotechnic layers, it is achieved that one or more of the damming layers are set in motion as early as possible, in order thereby to be able to disrupt the front fast parts of the hole charge jet, and so that one or more of the containment materials are set in motion more slowly, so that these can disturb the slower middle and rear areas of the hole charge jet.

The explosive layers can be embedded in one or more metallic or non-metallic materials with low density (15-30 kg/m ) and high compressibility as a matrix (see figure 6).

The design of the carrier 4 is completely free. In figure 1 it is shown as a curved surface. All that is necessary is that it has a sufficient slant in the area of effect in relation to the threat. Due to the high efficiency of the pyrotechnic coatings, in the device proposed here, the minimum angle will be 10° to 15° less than with the known reactive designs. Since, in connection with sandwiches of the usual type, a minimum inclination angle of 45° is assumed, in the present device an average angle of between 30° to 40° between the threat and the protection will be sufficient. The angle between the protected surface and the threat can be obtained by means of a placement of the entire surface or by means of geometrical modifications by means of technical or constructive measures. Thus, even with a relatively unsatisfactorily inclined surface, which is a threat to achieving a sufficient effect, the necessary inclination can be achieved, for example by making the surface wavy, angled or laminated. The various embodiments of the pyrotechnic protection surfaces can form a continuous surface or be made up of individual modules with spaces or other separations (for example surface segments, blinds, separate or interlocking modules).

The technical design of the carrier is basically not associated with any limitations (for example metallic, non-metallic, structured, single or multi-layer). The carrier can be rigid or deformable/movable, and its thickness can vary from foil thickness up to a solid plate or a thicker structure. Furthermore, the carrier can consist of an inert material or of a chemically/pyrotechnically reactive substance. Thus, an internal high-pressure field can also be built up in this carrier during the detonation of the pyrotechnic coatings.

The effect of a protective device is generally judged as the ratio between the reference mass (ammunition performance in armor steel equivalent) and the protective device's mass, using two factors: 1. Em factor, formed by: Em = mref / (mS + mRL), where mref is the threat's performance in steel-equivalent mass, mS is the protective mass used and mRL is the residual performance in steel-equivalent mass; as well as

2. Fm factor, formed by Fm = (mref - mRL) / mS.

The Em-factor serves as a rating scale for the quality of a total protection. In the case of a partial protection measure, i.e. in the case of a still occurring residual effect, the assessment of the individual protective devices takes place appropriately using the Fm factor, so that the qualities can be assessed in a comparable way.

According to the current state of the art, the Fm values achievable for passive protective devices are in the range 5, and for reactive devices in the range from 8 to 10.

A device in accordance with the invention basically requires the use of pyrotechnic substances with a dynamic in accordance with the application, i.e. a reactivity. The handling of the pyrotechnic elements required here and the associated safety measures and other operational requirements can be improved decisively by the necessary technical requirements for the carrier structure and the vehicle can be arranged as deeply as possible, precisely as a result of the advantages described above. Furthermore, with the help of similar measures, the investment time for an effective pyrotechnic coating can be minimized.

Figure 6 shows a principle structure in accordance with Figure 5A. The hole charge is placed at a distance 15 in front of the reactive protection device. In its simplest form, this consists of the explosive layers 16 and 17 tilted in relation to the beam axis 1. For purely fixing the explosive layers 16 and 17, the layers 18, 19 and 20 are used here. These layers 18, 19 and 20 can also act as very light damming. However, the necessary propagation speed to the surface must not be significantly reduced.

The protection device in figure 6 was tested under 45° and with an experimental charge of the type PG 7 of approximately 2.5 caliber and at a distance of 15. The protection structure consisted of foam/explosive/foam/explosive/foam, and the surface weight was at a density for the foam of approximately 15 kg/m<3>, less than 30 kg/m<2>in LoS (line of Sight). The experimentally recorded residual effect was approximately 30% of the impact of the hollow charge in armor steel. Based on this, a very high Fm value of over 70 was calculated. Furthermore, as in the following examples, ballistically relevant parts were formed neither in the direction of the threat nor in the direction of the object to be protected.

This confirms that such an extremely light device according to the invention is suitable as a general protection in connection with objects that generally require protection, as additional armor and in particular as protection for almost all vehicles. For vehicles with a high basic protection, for example tanks, such a device is very suitable for protecting the sides and rear against anti-tank small arms.

In another experiment, the forward explosive layer 16 was dammed with a relatively thin layer of medium density material. At a surface weight for the reactive protective device of approximately 100 kg/m<2>, the residual effect amounted to only approximately 10%. This gives an Fm value of over 25.

If one compares these experimentally recorded effects with values for known reactive protective devices, the difference in relation to protective devices according to the invention becomes completely clear, not only with regard to the residual effect (10% compared to previously approximately 30%), but also with regard to the surface weight (~100 kg) /m<2>compared to 300 kg/m2).

In yet another attempt, not only the front explosive layer 16, but also the rear explosive layer 16 was dammed on the carrier side with a brittle material of medium density (20, 20A) (Figure 7). As a result of the relatively thin inner layer of foam material 19, this concerns a particularly flat protective structure of the type shown in figure 5B. At a surface weight for the reactive protection device of less than 90 kg/m<2>, the residual effect amounted to less than 10%. This gives an Fm value of over 30.

The residual effect of the hollow charge must be compensated with ballistically effective materials. Since even materials such as armor steel, high-strength duralumin or titanium only have efficiencies up to 1.5, the special effect of a protective device according to the invention becomes clearly noticeable, especially with regard to an application for light systems. The achieved very small residual effects confirm that the use of such a reactive protection device according to the invention for medium or even lightly armored vehicles is possible.

This is confirmed with an experiment which included a reactive protection device shown in Figure 8. In this combination of the devices shown in Figures 5 and 6 (front coating: thin layers of medium density 21), a bulge device 22 was arranged on the target side after an explosive layer 17 embedded in foam material 19, 20. At a surface weight for the entire protective device of approximately 170 kg/m<2>, the residual effect was only approximately 1% to 2%.

A comparison of the absolute values for these reactive protection devices according to the invention with reactive protection systems according to known technology, makes clear the significant level of innovation for the invention. Common reactive protection systems with an area weight of 300 kg/m<2>, in the most favorable case, achieve residual effect values of 20% of the reference effect of the threat, i.e. a residual effect of 60 mm to 80 mm of armor steel in the case of a threat from anti-tank small arms with a possibility of effect on father 300 mm to 400 mm armor steel equivalent. This corresponds to a surface weight of from 480 kg/m<2> to 640 kg/m2. In the best case, a total surface weight of 780 kg/m<2> is thus achieved for the required armor protection. If the object surface to be protected is, for example, 6 m2 (e.g. side protection), then you need a total protection weight of 4,680 kg. For comparison, the residual effect of the reactive protection device according to the invention is only a maximum of 10 mm armor steel equivalent, which corresponds to a surface weight of 80 kg/m<2>. Summed up with the surface weight of the protective device according to the invention, a total surface weight for the required armor protection of 250 kg/m<2> thus appears. For the object to be protected, this means, with a protection surface of 6 m<2>, a total protection weight of only 1,500 kg, i.e. that the weight saving compared to known reactive protection systems amounts to 3,180 kg. With a reactive protective device according to the invention, one thus only needs approximately 32% of the protective mass required in conventional reactive protective devices.

The pyrotechnic coating of the protective surface can be in the form of a real coating, a fixed or applied explosive foil, an applied reactive mixture (for example metallic additives to increase the disruptive effect) or also consist of a rigid or deformable container (bag) containing a pyrotechnic agent . However, the walls must be designed so that the described operation of the pyrotechnic protection surface is not adversely affected. However, this effect will be ensured when coating thicknesses of the fast components in the order of tenths of a millimeter are used. The metallic or non-metallic covering of such a container or the surface of the explosive film will also depend on the production method used. Moreover, such enclosures or surfaces may also be necessary for protection against handling and use loads as well as against environmental influences.

Pyrotechnic protective surfaces can be easily combined to achieve the required resistance, also against relatively strong or large threats. Thus, a new and highly effective protective surface is formed when two relatively thin pyrotechnic protective surfaces are connected, even though the total explosive thickness will still be somewhat smaller than with the known reactive armours. By using two pyrotechnic protection plates, as a result of the greatly reduced residual effect, it will be possible to reach these high effectiveness values, or in a very effective way to also be able to ward off larger hollow charges. This also applies to tandem devices.

All the possibilities applicable to the ignition of the pyrotechnic surface can be derived or transferred from known reactive protection devices. This includes a release as a result of a direct hit or via ignition aids, which also includes a controlled foreign ignition. One can also derive or transfer from this all the possibilities available for dressing or sheathing a pyrotechnic surface. This includes the introduction (or packaging) in a clean protective film (for example as protection against weather and wind, for impact or contact protection during transport or a coloring of the surfaces).

Further advantages and possibilities regarding the design, which can be derived or transferred from known reactive protection devices without special knowledge, relate to the design of a housing and fixings, including dismantability and thus replaceability and mobility (insertion, turning, tilting). This also applies to the positioning at a distance in front of the object using fastening elements or intermediate layers. Of course, these must not affect the function in a negative direction. Intermediate layers or spacers can for example be thin structures, fabrics with very low density or air chambers. Other points relate, for example, to modular structures, multi-layer devices, changes to the carrier thickness and the thickness of pyrotechnic coatings and a variation of the participating effect components. Of course, arbitrary layers or structures (for example curved, wavy or angled surfaces) can also be coated with a pyrotechnic protective surface on one or both sides.

The highly effective reactive protective devices or protective surfaces according to the invention also make unnecessary the use of very complex and easily disturbed active protection technology to a large extent. Such systems should provide a further increase in protection compared to classic reactive protection systems, especially where the threat can no longer be averted with the object itself, even with effective, known reactive devices, or where the object to be protected with the reactive armor, in itself will be overloaded or even destroyed.

Even where active protection systems are arranged, the reactive surfaces according to the invention can bring a decisive advantage, as such modules will be able to provide great protective effects even with the smallest surface dimensions and also with arbitrarily shaped or very small element sizes. This applies in particular to actively accelerated protection elements, as these, in accordance with the very small masses, only require relatively little energy for the acceleration.

Below are the basic advantages of pyrotechnic protective surfaces or protective devices: The pyrotechnic protective device or protective surface has a

minimal surface weight.

The pyrotechnic protection device or the protective surface needs

only a minimal construction depth.

The pyrotechnic protective surface is basically a free element and is

thus not tied to other technical devices.

The pyrotechnic protection device has an optimal overall efficiency

with regard to mass and depth of protection.

There are no restrictions with regard to a flat-like structure or with regard to the design, nor with regard to the depth of protection. This also enables extremely flat construction methods (order of magnitude: 20%

to 30% of the HL reference penetration effect in armor steel).

Even very small element sizes can be realized, because the edge influence (for example on the dam) compared to normal reactive

armours, is much less.

The device can adapt the angle of inclination to the required surface to any extent

be protected.

- As a module, the pyrotechnic surface can be placed arbitrarily, for example as a single or multi-layered armouring, as impact surfaces in connection with skirts or

also directly as a skirt.

The HL beam is loaded in two different directions, with minimal reaction time and at the same time

with a large span of time.

- Apart from a generally unproblematic blast pressure, no structural loads occur. This avoids deformations in the supporting structure.

The surroundings are not loaded with final ballistically relevant masses.

- The pyrotechnic protection surface can be arbitrarily designed and can be adapted to any surface or internal structure.

The pyrotechnic protective surface can be rigid or deformable/movable. The pyrotechnic protective surface can be fixed or releasably attached in arbitrary ways to the existing surfaces.

- The pyrotechnic protection surface can be suspended or stretched as a rigid or movable curtain in a frame or loose in front of an object to be

be protected.

- Pyrotechnic protection surfaces can be located on one or both sides of arbitrary layers or structures.

An arbitrary build-up of technically independent protective surfaces and combinations of these is made possible. Thus, for example, parallel or

mutually inclined pyrotechnic protection surfaces are combined.

- The pyrotechnic surface can be used as a separate device or it can be combined with other armor (for example against weight (KE and FK threats)). - The pyrotechnic protection device can be effectively combined with bulge plate devices, because the high jet velocities are thus reduced

that thereby the effect of bulge plate devices (bulge sandwiches) is increased. Pyrotechnic surfaces can be used as very effective multi-layered surface modules, for example, against threats from relatively coarse-calibre mono-hole charges or F£L tandem threats.

The pyrotechnic protective surface makes no special technical requirements (for example with regard to manufacturing methods, manufacturing tolerances and

explosive homogeneity).

- In relation to the protective effect achieved, the production costs for the protective surfaces are low.

With pyrotechnic protection surfaces, many options are made possible for adding to existing structures, vehicles or other surfaces to be protected (also as additional armor for already existing inert or

reactive armors).

By using or replacing reactive components with many of the known reactive protection devices, a technical improvement of the entire

the structure.

Pyrotechnic protective surfaces can be adapted to the technique without much effort

condition.

Even with different coating thicknesses or element masses, a dynamic equilibrium can be achieved by suitable design or dimensioning of the other components. The carrier of a pyrotechnic protection device can consist of an inert material

or be in the form of a hollow or filled structure.

The carrier of the pyrotechnic protection surface can be minimized as a pure attachment/mounting surface or, depending on the design (for example, a multi-layer structure or technical structure), satisfy ballistic or technical additional requirements within wide limits. This can be achieved without a reduction/destruction of the device's basic effect. - For the housing and for the attachments to the pyrotechnic surface, all of the known advantages of such devices are retained.

If necessary, the side, roof and bottom surfaces of a house or container can also

are coated with pyrotechnic protective surfaces.

By means of pyrotechnic protective surfaces according to the invention, a very effective protection against HL threats for light vehicles or non-armored devices is made possible for the first time. - By means of pyrotechnic protection devices according to the invention, a very effective protection against large-calibre HL threats is made possible for medium-heavy armored vehicles for the first time.

Pyrotechnic protective surfaces can be used in addition to and/or as impact components in connection with active armor.

Pyrotechnic protection surfaces can also serve as impact surfaces in the case of active armor as well as in signal transmission (detonation transmission).

In the reactive protection device, the respective explosive layers can optionally be enclosed by one or more chambers supplied with fillers or air. Other embodiments of the invention shall be discussed in more detail below, particularly with regard to application and use, in the case of light vehicles or means of transport.

Particularly advantageous is a flexible housing, which encloses the explosive layers that are not or partially dampened. The housing (see figures 9 to 11) can be made of an elastic, metal-free and non-split material used, such as, for example, elastomers, thermoplastics or duro-plastics. Other possible materials are foam or sinter materials, fiber composite materials, a material from re-growing raw materials, wood or synthetic wood, an organic material (paper, leather), a textile material or a combination of these materials. With a complete integration of one or both layers of explosives in the house walls, a dynamic containment of the detonating explosives is achieved. This can give a further increase in the protective effect. Furthermore, the explosives layer facing the combat area can also be protected against small caliber ammunition by means of a composite armour.

The three devices described in more detail below serve to illuminate the virtually unlimited design possibilities that exist for containers, respectively houses. Thus, for example, Figure 9 shows an example of a pyrotechnic device 23, where the housing 28 has a vertical rear wall. Behind the thin front cover 24 lies the front pyrotechnic layer 25, and then follows an intermediate layer 27, consisting of air or of a medium of very low density. Another pyrotechnic layer 26 is arranged between 27 and the rear (filled or free) volume 29.

The reactive protection can, with or without housing, be arranged directly on or at a distance from a bulge device on the vehicle. The bulge structure consists of a front metallic or non-metallic layer, a dynamically acting functional layer, for example rubber, and a rear metallic or non-metallic layer, which can for example be the outer wall of the vehicle (for example stowage boxes etc). Figure 10 shows such an example of a pyrotechnic device with a connected bulge sandwich 30. Here, the pyrotechnic layers 31, 33 are arranged at different angles. The front explosive foil 31 is embedded in the front of the house. The house's inclined rear wall 36 has different thicknesses. The space 32 is here empty, thereby enabling the greatest possible surface speed for the foil 33 coated with the thin layer 27. Behind the medium with a low or very low density 34, a bulge plate sandwich 35 is arranged. The rear space 37 is either empty or filled with a medium with a very low density. Figure 11 shows an example of a pyrotechnic device 38 with an open housing 39 at the back, which is here placed directly on the wall 40 of the object to be protected. The device 38 has a continuous front pyrotechnic surface 41, while the inner pyrotechnic surface is divided into two components 45, 46, which can for example be separated from each other by means of an intermediate wall 44. The chambers 42 and 43, as well as 47 and 48, can be filled with air or with media of different or similar, very low densities.

In a preferred embodiment, the layers of explosives and inert materials are introduced into pre-provided pockets in the container or housing, whereby a simple and manufacturing-technical adaptation of the reactive protection to the vehicle to be protected is made possible. It will also be possible to replace components in a simple way, for example to replace pyrotechnics with inert modules. Likewise, several reactive partial surfaces can be combined into one protective surface.

Depending on the material, the housing can be produced using vulcanisation, casting, gluing, pressing or chip-working methods. One can also imagine combinations of all the manufacturing methods mentioned here. Furthermore, the house can have an armor ring or constitute one itself. The housing can contain one or more cavities of the same or different size, where the inert and explosive materials in the pyrotechnic protection structure can be inserted, pushed in, embedded or pressed in. The wall thickness can be uniform or have different thicknesses. The latter will be advantageous when the house is part of the protective layer or itself represents an inert and protective dam. The housing can be designed so that it can be assembled to achieve a fixed or flexible contour. This arrangement of the structure prevents an expulsion of protection modules when the vehicle collides with obstacles and/or is under fire. Certain segments of the wall can be moved, bent away or rolled up, so that you can gain access to underlying vehicle areas. The wall segments can be removed or added with the help of a few hand movements.

In a suitable embodiment, the house is designed so that it overlaps neighboring houses at the edge areas. This will ensure that, even in the event of a hit in the edge area or directly against the edge of the house, there will be sufficient damming material. Particularly advantageous is an embodiment where the house wall in the area where adjacent houses have a wall thickness that will be able to reliably prevent sympathetic detonations of the explosive layers of adjacent modules when a hit occurs outside the overlapping areas.

The fastening elements can be vulcanised, cast, glued or suspended on the housing. Advantageously, the fastening elements are of a material that does not form splinters and has a high toughness, so that the non-detonating modules on a vehicle will remain in place when adjacent modules detonate. The fastenings can be reinforced with high-strength fibers and/or high-strength inserts made of polymer or steel.

The house walls are designed to be compliant so that they can withstand long-term thermal loads (fire, radiant heat). The maximum internal pressure at longer loading times can be limited by means of constructive measures for the housing, so that a non-sensitive explosive can burn without detonation occurring.

In the house, one or more separate chambers can be arranged. These can be limited by the explosive layers, the respective matrix material and the housing material, possibly in combination. These chambers can be filled with substances that split and do not form impact splinters, and such substances can be, for example, gases, solids, liquids, gels, crystals, fibers or radioactive material. The cavities in the wall or in the house can be used as containers for fuels, liquids or also as storage spaces, for example for placing equipment. These cavities in the housing can also be pressurized with gases or liquids, in order to thereby be able to move the reactive HL protection according to the invention from a space-saving transport position to a protective position.

The houses can be arranged so that they form continuous slots, which individually or together can be rolled up or folded together when the vehicle is to be maintained. The house or parts of the house can also be designed as packaging for explosives, for storage, handling and carrying on the vehicle and transport, within the regulations of GGVS. In order to avoid an internal pressure critical for the explosive, membranes or overpressure valves can also be arranged which serve to limit the internal pressure in the housing. The housing material and housing shape must be optimized for decontamination.

From the above description and explanations, including also an indication of the principle advantages of the pyrotechnic protection device and the protective surface according to the invention, it appears that the invention does not even come close to achieving technical effectiveness values, while the invention can be used within very wide limits. One thus achieves an almost unlimited application bandwidth and modularity. This is a broad area which, in the case of armored vehicles, includes all-round protection, with movable or fixed skirts, and also roof protection etc. It is also conceivable to protect bottom surfaces against threats of the aforementioned type. In addition, pyrotechnic protective surfaces will also represent a very effective protection for containers or building constructions.

Although the present invention has been described above with reference to several possible embodiments, it will be clear to a person skilled in the art that many changes and modifications can be imagined within the inventive framework given by the patent claims.

Claims (9)

1. Reactive protection device for an object to be protected, in both functional directions without splinter formation that is relevant in relation to final ballistics, comprises two inclined pyrotechnic layers (2, 3) in relation to the threat in the area of effect and which are arranged on both sides of a rigid or flexible single or multi-layer intermediate layer (4) with arbitrary shaping, characterized by; the intermediate layer (4) acts as a carrier for the two pyrotechnic layers (2, 3) so that after the ignition of the two pyrotechnic layers (2, 3) shock waves and reaction gases are formed, which are thus accelerated at an angle both towards and in the direction of the penetrating threat (1) in such a way that the pyrotechnic protective surface formed by the two pyrotechnic layers and the intermediate layer is placed in a state of dynamic equilibrium almost throughout the duration of action; the intermediate layer (4) is designed in the foil thickness and the pyrotechnic protection surface formed by the two pyrotechnic layers (2, 3) and the intermediate layer (4) has a weight in relation to the surface area of less than 90 kg / m<2>. 2. Reactive protection device according to claim 1, characterized in that at least one of the pyrotechnic layers (2, 3) has a free surface or is dammed up (13, 13A, 14, 14A) on one or both sides. 3. Reactive protection device according to claim 1 or 2, characterized in that two or more pyrotechnic layers (2, 3) are arranged parallel or at an angle relative to each other on the object to be protected. 4. Reactive protection device according to one of claims 1 to 3, characterized in that the pyrotechnic protection surface formed by the two pyrotechnic layers (2, 3) and the intermediate layer (4) is arranged in a housing (28). 5. Reactive protection device according to claim 4 Reactive protection device according to claim 6, characterized in that one or more chambers (42, 43, 47, 48) are arranged in the housing which are separated from each other, and which are empty or filled with substances such as gases, solids, liquids, gels, crystals, fibers or stock. 6. Reactive protection device according to one of claims 1 to 5, characterized in that the pyrotechnic layer (3) arranged on the object side has a bulge device (22, 35) located behind, which is directly adjacent or arranged at a distance. 7. Reactive protection device according to one of claims 1 to 6, characterized in that at least one of the pyrotechnic layers (17) is arranged between two layer-bearing layers (19, 20). 8. Reactive protection device according to one of claims 1 to 7, characterized in that the intermediate layer (4) is made of a chemically/pyrotechnically reactive substance. 9. Active reinforcement arrangement for an object to be protected, to which a pyrotechnic protection surface formed by two or more pyrotechnic layers (2, 3) and an intermediate layer (4) of a reactive protection device according to one of claims 1 to 8 is integrated.