EP1221017A1 - Propellant device for pipe weapons or ballistic projection - Google Patents

Abstract

The invention relates to a propellant device for pipe weapons (10) or ballistic projection, comprising a compact charge (1) and a firing system. Distributed within the compact charge is at least one electromagnetic radiation absorbing medium (3), for example, carbon black. Said medium can be activated by means of the electromagnetic radiation emitting firing system. The compact charge is thus broken into fragments upon releasing the firing system and said fragments are accelerated in the gas volume generated by the burning of the compact charge. The inventive propellant device avoids the need for chemical or mechanical igniters and, by means of the fragmentation of the compact charge, maintains the generated maximal pressure for a longer period which lends the object to be accelerated such as a projectile, rocket or similar a higher muzzle velocity.

Description

 Propellant charge arrangement for barrel weapons or ballistic drives

The invention relates to a propellant charge arrangement for barrel weapons or ballistic drives, consisting of a compact charge and an ignition system.

In the case of chemically reacting propellant charges, the power is essentially determined by the ratio of the mass of the charge and its energy density to the mass of the object to be accelerated, e.g. a projectile, a missile or the like. The aim is always to match the mass of the propellant charge and its energy density to the specific need. For the muzzle velocity of the projectile, the internal ballistics, i.e. the ignition process and the combustion of the propellant charge, as well as the transfer of energy to the projectile before leaving the barrel, are of particular importance.

The erosion of the propellant charge and the acceleration of the projectile is a dynamic process that takes place in an extremely short time, within which the gas development due to the propellant charge not only matches the mass of the projectile, but also takes into account the fact It must be ensured that the volume to be filled by the propellant gas increases with the acceleration of the projectile. These overlapping processes must in turn be coordinated with one another in such a way that the projectile reaches the desired muzzle velocity. Decisive for this is the gas pressure-time curve, which is generally similar to a Gauss curve, ie the pressure rises exponentially to a maximum pressure and drops a little less steeply with increasing projectile acceleration towards the muzzle. A similar characteristic with a somewhat more symmetrical course of the Gaussian curve shows the rate of conversion of the propellant charge. The decisive factor for the drive power is the pressure-time integral, which is limited by the maximum permissible gas pressure in the cargo area. The ideal case would be a trapezoidal pressure curve in which the maximum pressure is reached faster and at the same time the integral of the pressure-time curve should be larger.

In order to achieve a high muzzle velocity of the projectile, propellant charges with high charge density, that is to say a large ratio of the mass of the propellant charge powder to its volume, are generally used as compact charges. Here, the high charge density required for a high muzzle velocity of the projectile is made more regular by large-volume propellant charges

Arrangement of the charge particles achieved. The ignition is made by chemical ignition means, e.g. Nitrates, which require mechanical ignition devices, such as firing bolts, or electromechanical ignition devices.

On the one hand, it is disadvantageous that such ignition means are sensitive to environmental influences, such as heat or moisture, and can lead to untimely ignition. On the other hand, when igniting it must be ensured that the resulting swaths of the ignition agent are as possible with a contact the large surface of the propellant charge, otherwise the linear burn rate of the propellant charge is too low to burn off the entire charge in a short time or to achieve the pressure required for the desired muzzle velocity of the projectile. In order to form the reproducible burn-off surfaces required for a reproducible increase in pressure, tubular powder or cylindrical multi-hole powder, for example, are used, which are penetrated by channels for the passage of the vapor of the igniter, so that the burn-off of the propellant charge is initiated on a large surface. However, this lowers the density of propellant and reduces the muzzle velocity of the projectile. Furthermore, the gas pressure drops exponentially again immediately after reaching its maximum. While burn-up times of 1 to 10 ms are achieved in this way with small-caliber barrel weapons, such as anti-aircraft guns or tank cannons, the burn-up times are much longer with large-bore barrel weapons, such as artillery pieces.

Furthermore, compact charges that can be initiated by means of electrical energy (electrothermal-chemical cannon) are known, but the ignition and burning off of such compact charges is difficult because the charge arrangement has to be broken up and disassembled and defined surfaces have to be created in order to achieve the desired muzzle velocity required burn-on and burn-off is achieved with a high turnover rate of the propellant charge.

The same applies to the liquid propellant charges which have recently been investigated and which have to be converted into an appropriate dispersion.

DE 195 46 341 AI describes a propellant charge with a secondary arranged in a cylindrical sleeve Explosives and an initial explosive arranged next to this, which is ignited by coupling in laser radiation. A high rate of conversion of the propellant charge during combustion cannot be achieved with such an arrangement, since the initial explosive is arranged only on one side of the secondary explosive facing an optical fiber and the latter is consequently not spontaneously broken up and disassembled when the charge is detonated.

DE 35 42 447 A1 shows an ignition mixture which can be activated by means of laser radiation and which contains 10 to 30% by mass of a hot-burning fine particulate metal powder, in particular zirconium, titanium or boron, 60 to 80% by mass of an oxidizing agent, in particular lead oxide, and 1 contains up to 5% by mass of carbon black. To ignite a propellant charge, the ignition mixture is arranged in a narrow geometric area of the charge powder of a few mm ² , on which the laser beam strikes. In this case too, a spontaneous conversion of the charge powder is not possible.

The invention is based on the object of proposing a propellant charge arrangement which, as far as possible, approaches the ideal trapezoidal course of the pressure-time curve while avoiding the abovementioned disadvantages during combustion.

According to the invention, this object is achieved by a propellant charge arrangement of the type mentioned at the outset in that at least one medium absorbing electromagnetic radiation is distributedly distributed in the compact charge and can be activated by means of the ignition system which emits electromagnetic radiation, in order to fragment the compact charge when the ignition system is triggered disassemble and the fragments in to accelerate the gas volume generated when the compact charge burns.

Due to the internal ignition of the propellant charge arrangement according to the invention at the areas absorbing electromagnetic radiation, the compact charge is broken down into fragments in a defined sequence. The structure of the compact charge and its arrangement, as well as that of the ignition system, can be selected so that fragments with a relatively regular geometry are created, which consequently also offer relatively regular surfaces, which in turn ensure regular burning and burning. Likewise, by increasing the introduction of the medium absorbing electromagnetic radiation into defined areas of the propellant charge, it is possible to ignite these areas earlier and thus control the erosion as a function of time. The fragments resulting from the fragmentation have a large burn-off area and are accelerated into the gas volume developing when the propellant charge burns up, and are fully implemented there. In this way, for example in the case of a barrel weapon, the increase in volume and decrease in pressure associated with the acceleration of the projectile are immediately compensated for. This structure of the propellant charge arrangement allows the resulting maximum pressure to be maintained over a longer period of time, so that instead of a peak there is a pressure plateau in the pressure-time diagram in order to accelerate the projectile with a longer-lasting gas pressure. As a result, the maximum pressure and the muzzle pressure can be reduced without the drive line or the muzzle velocity falling. Accordingly, a significantly higher muzzle velocity can be achieved at the same maximum pressure.

The propellant charge arrangement according to the invention makes the use of chemical ignition means unnecessary, as a result of which it b is easier and safer to handle. Furthermore, it does not require any mechanical or electromechanical ignition devices required to initiate such chemical ignition means, so that its simple construction makes it cost-effective.

Furthermore, the density of the propellant charge arrangement according to the invention can be increased significantly compared to conventional propellant charges by making the deposits of the medium absorbing electromagnetic radiation very thin, so that they require a significantly smaller space requirement in comparison to the channels provided in conventional propellant charges for swath penetration.

The formation of fragments with a relatively regular geometry and consequently a high erosion surface can be achieved in particular in that the compact charge has an essentially regularly structured structure and the electromagnetic radiation-absorbing medium is embedded in the compact charge in a regular arrangement. The triggering of the ignition system of the compact charge is then broken along the area from the electromagnetic radiation-absorbing medium and in accelerated ent ^¬ speaking regular fragments inward with the forming surfaces for proper check-in and burn care.

The compact charge can be interspersed, for example, with layers of the electromagnetic radiation-absorbing medium that are arranged essentially geometrically regularly, the layers preferably being arranged essentially in a grid-like manner. Depending on the type of explosive and the medium absorbing electromagnetic radiation, the layer thickness is expediently between 1 and 1000 μm. The compact charge can also be interspersed with channels of the electromagnetic radiation-absorbing medium which are arranged essentially geometrically regularly, the diameter of the channels advantageously being between 1 and 1000 μm.

An essentially disperse arrangement of the medium absorbing electromagnetic radiation in the compact charge is also conceivable, wherein the disperse inclusions can be arranged either statistically or essentially geometrically regularly, in particular in a grid-like manner.

In any case, the medium stored in the explosive and possibly enveloping the electromagnetic radiation absorbing medium can be stored in any way, e.g. lead to ignition of the compact charge or fragmentation thereof by heating and, if appropriate, the thermal expansion and / or evaporation associated with the heating, photo-reaction, cleavage, conversion into a plasma state or the like. The compact charge can either be essentially powdery, the powder particles having a structure of the aforementioned type, or the compact charge is designed in the manner of a molded part, which is e.g. can be introduced into a cargo space of a barrel weapon.

In a development of the invention it is provided that the intensity and / or the spectrum of the electromagnetic radiation of the ignition system can be controlled. By controlling the electromagnetic radiation in terms of time or location, the pressure-time profile can be influenced in a targeted manner, for example on the one hand by specifically re-igniting the fragments formed or by heating the combustion gases by passing the electromagnetic radiation onto the Resonance frequency of the same is adjusted. For example, a pulsed coupling of the electromagnetic radiation with a possibly variable frequency is conceivable until the projectile emerges from the muzzle of the barrel weapon. It can also be used to ignite the

Compact charge used electromagnetic radiation to be adapted to the ambient conditions, so that e.g. at an increased ambient temperature, which brings about an increased burn-up rate, the intensity of the radiation can be reduced in order to activate only a part of the deposits from the electromagnetic radiation-absorbing medium, to reduce the fragmentation of the compact charge or the burn-off surface and the To compensate for the temperature-related increase in the burning rate.

A preferred embodiment provides that the electromagnetic radiation has a wavelength of approximately 1 mm to approximately 1 m (microwaves). Of course, depending on the type of medium absorbing electromagnetic radiation, electromagnetic radiation of other wavelength ranges, e.g. Ultraviolet, infrared or the like. In question, the wavelength ranges can be either laser-like narrowband or plasma-like broadband. The spectrum of the electromagnetic radiation depends primarily on the absorption spectrum of the respective electromagnetic radiation-absorbing medium, it being necessary to ensure that the medium used for the selected wavelength range has a higher absorption capacity than the respective explosive of the compact charge.

The electromagnetic radiation can be coupled into the compact charge, for example, by means of an emitter reaching into the compact charge, such as an antenna, or the electromagnetic radiation can be coupled into the compact charge by means of emitters surrounding the compact charge. In any case, the compact charge can be arranged in a cartridge, which is particularly advantageous for handling an essentially powdered propellant charge.

Carbon, in particular soot, is preferably used as the medium absorbing electromagnetic radiation, on the one hand because of its compatibility with most explosives, and on the other hand because of its high absorption capacity for electromagnetic radiation in a wide frequency range.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings. Show it:

1 shows a cross section through a propellant charge arrangement according to the invention for tubular weapons.

2 shows a schematic view of a propellant grain according to the invention;

Fig. 3 is a pressure-time diagram of a conventional propellant charge with chemical igniters and

Fig. 4 is a pressure-time diagram of a propellant charge arrangement according to the invention.

1 shows a schematic cross section through a barrel weapon 10 with a barrel 12 (shown broken off) and a cargo space 11 in which a propellant charge 4 is accommodated in the form of a compact charge. The compact fertilizer 4 consists, for example, of a powder made of an explosive or an explosive mixture and a medium, such as soot, which is used to store electromagnetic radiation. As shown in FIG. 2, the electromagnetic radiation-absorbing medium 3 is embedded in the propellant charge particles 1 of the compact charge in a regular arrangement, passing through the explosive 2 in layers arranged in a grid. There is a projectile 13 in barrel 12, the rear of which projects into cargo space 11. An ignition system 5 with a controllable microwave generator 6 is provided for igniting the propellant charge 4. The electromagnetic radiation generated by the microwave generator 6 can be coupled into the cargo space 11 via an antenna 7.

After the compact charge 4 has been ignited by means of the microwave generator 6, the particles 1 of the compact charge 4 are broken down into essentially regular fragments along the soot layers 3 and the fragments are accelerated into the gas volume generated when the compact charge 4 burns up. At the same time, the fragments burn off and the fuel fragments from the compact charge 4 are converted. The projectile 13 is subjected to an approximately constant pressure over a longer distance and leaves the barrel 12 with the desired high muzzle velocity with a possibly reduced muzzle pressure.

3 shows the pressure-time profile of a conventional propellant charge with curve 15. The pressure p increases exponentially to a maximum pressure p _max and drops somewhat less steeply with increasing acceleration, the projectile towards the muzzle.

As can be seen from FIG. 4, the propellant charge arrangement according to the invention enables a pressure curve according to the curve Generate 16, which shows a pronounced pressure plateau 17 with a time-delayed pressure drop with a somewhat leading rise. In this way, with an increased drive power, for which the pressure-time integral is decisive, the maximum pressure p _{max can be} reduced or an increased drive power can be achieved with the same maximum pressure.

Claims

claims 1. propellant charge arrangement for barrel weapons or ballistic drives, consisting of a compact charge and an ignition system, characterized in that at least one medium absorbing electromagnetic radiation is distributed in the compact charge and can be activated by means of the ignition system emitting electromagnetic radiation in order to trigger the compact charge when the Disassemble the ignition system into fragments and accelerate the fragments into the gas volume generated when the compact charge burns. 2. propellant charge arrangement according to claim 1, characterized in that the electromagnetic radiation-absorbing medium is embedded in the compact charge in a regular arrangement. 3. Propellant charge arrangement according to claim 1 or 2, characterized in that the compact charge is interspersed with layers of the electromagnetic radiation-absorbing medium which are arranged in a substantially geometrically regular manner. , Propellant charge arrangement according to claim 3, characterized in that the layers are arranged essentially in a grid pattern. 5. propellant charge arrangement according to claim 3 or 4, characterized in that the layer thickness is between 1 and 1000 microns. 6. propellant charge arrangement according to claim 1 or 2, characterized in that the compact charge is penetrated by substantially geometrically regularly arranged channels from the electromagnetic radiation absorbing medium. 7. propellant charge arrangement according to claim 6, characterized in that the diameter of the channels is between 1 and 1000 microns. 8. propellant charge arrangement according to claim 1 or 2, characterized in that the electromagnetic radiation absorbing medium is arranged in the compact charge substantially disperse. 9. propellant charge arrangement according to one of claims 1 to 8, characterized in that the intensity and / or Spectrum of the electromagnetic radiation of the ignition system is controllable. 10. propellant charge arrangement according to one of claims 1 to 9, characterized in that the electromagnetic Radiation a wavelength of about 1 mm to about 1 m (Microwaves). 11. propellant charge arrangement according to one of claims 1 to 10, characterized in that the electromagnetic radiation can be coupled into the compact charge by means of an emitter extending into the compact charge. 12. propellant charge arrangement according to one of claims 1 to 10, characterized in that the electromagnetic Radiation can be coupled into the compact charge by means of emitters surrounding the compact charge. 13. propellant charge arrangement according to one of claims 1 to 12, characterized in that the compact charge is arranged in a cartridge. 14. Propellant charge arrangement according to one of claims 1 to 13, characterized in that carbon, in particular soot, is used as the electromagnetic radiation-absorbing medium.