SE460538B - FUEL CHARGING FOR STERLED WEAPONS - Google Patents

Description

460 538 set larger grains. A disadvantage is furthermore the relatively small mechanical strength of such grains against shock wave impact, especially if the grains do not consist of single crystals, but of fused crystals.

Due to the above-mentioned disadvantages, the use of the known propellant masses is limited to small and medium-sized calibers.

The object of the present invention is to provide cheap, efficient and fire-stable propellant masses for all calibers and ejector devices.

This is achieved by the proportion of foam plastic, e.g. polyurethane, constitutes 15-25% by weight, that the proportion of secondary explosive constitutes 5-35% by weight and that the proportion of different sized ammonium nitrate grains constitutes 40-80% by weight of the mass, the ammonine nitrate grains having a size of 0.8 - 2.0 mm.

Additional advantageous further embodiments appear from t, the subclaims. If the quantitative compositions are determined to a large extent: D by the surface of the substance which exhibits the best reactivity and reaction rate. In practice this means that nowadays nitroamine grain fractions can be used, which are common in the explosives technique (grain fractions of 0.1 - 1.0 mm), and easy to produce. The small breaking tendency in the event of a shock wave is another advantage.

The use of ammonium nitrate in finely ground form, with a grain size of 5-50 μm is previously known both from the production of propellants for firearms based on nitrocellulose resp. nitrocellulose-nitroglycerin, as from the production of rocket propellants on a plastic basis (Composite). According to the invention, however, commercially available ammonium nitrate with a grain size of 0.9 - 2.0 mm was also used, which is embedded in a porous plastic mass with a density of 0.5 - 1.2 g / cm 3. In the case of the above-mentioned conventional fuels, on the other hand, a compact matrix without porosity and a density of 1.4 - 1.6 g / cm3 must be present, otherwise an uncontrollable rapid combustion occurs.

By using exclusively large grains, it is possible to keep the nitroamine content very low without energy loss and to achieve a fire rate, which is common and necessary for tubular firearms at a pressure of 2500 - 5000 bar. In addition to pure ammonium nitrate, large grains can also be used, which contain e.g. 460,538 potassium nitrate as an additive for changing the conversion point.

Addition of additional orifice flame retardant constituents is not required.

Through the thinly inspected nitroamine, the mechanical strength of the active substance increases significantly and a homogeneous distribution in the propellant charge mass is achieved thanks to the smooth surface of the substance.

The thickness of the layer is so adapted that it seems phlegmatizing as little as possible. The layer covers and smoothes irregularities in the single crystal, e.g. tips, dangers, grooves, edge or fracture surface widths, etc .. Despite the same grain size, the surfaces will no longer be different. This has a stabilizing effect on fire properties. A minimum distance between the individual, uninspected explosive grains is achieved with equal distribution through the large ammonium nitrate grains. In the event of a nest formation, said layer counteracts the higher reaction rate and a steeper and higher pressure increase is thereby certainly avoided.

The layer also prevents the formation of explosive dust, so that different size reaction surfaces do not arise. In addition, by increasing the strength of the single crystals, breakage due to shock- wave impact. In the event of a fire in the propellant mass, the growing gas pressure has no influence on the design of the single crystals. There are no uncontrolled new surfaces, which otherwise lead to pressure peaks.

The propellant masses according to the invention are very inexpensive, made of easily accessible material, through precisely specified starting products directly miscible or foaming in the cartridge within the low temperature range, and precisely reproducible in terms of their power data such as energy content per unit volume. They can also be inserted in the form of sleeveless propellant masses.

For optimization of the propellant mass to the desired fire speed resp. viability, the following parameters are available within the scope of the above composition: - chemical influences; - the percentage of the most reactive component nitroamine; - the percentage of the oxidizing agent ammonium nitrate; the addition of other gas-forming substances such as nitroguanidine; physical influence quantities, 460 538 '- - the grain size of the nitroamine; - density of the propellant mass (porosity); - the charge density in the combustion chamber; - the strength of the inserted granulation (core form); - the surface layers.

The following effects affect the rate of fire: - the ratio between surface area and volume of the nitroamine and the oxidizing agent ammonium nitrate; - the proportion of PUR foam (phlegmatizing).

The interplay between phlegmatization and the critical diameter of the inserted explosive (nest formation) can be regulated so that it does not lead to any overreaction, e.g. pressure peaks. Due to their lower proportion of secondary explosives, the masses according to the invention show better safety properties than known techniques. An effect that is achieved with conventional propellants.

The invention will be described in more detail below with reference to the accompanying drawing, in which Fig. 1 shows the constituents of a mass with even distribution; Fig. 2 shows the constituents of Fig. 1 with uneven distribution; and Fig. 3 shows the components according to Fig. 2 in another embodiment.

Fig. 1 shows an even distribution. In a polyurethane foam plastic 1 are large grains 2 of ammonium nitrate and with a gap 3, grains 4 of nitroamine, e.g. octogen. P.g.a. the alternating arrangement of said constituents there is an even distribution, i.e. ideal conditions for firing (direction 5) of said constituents. The foam 1 in the spaces 3 has a phlegmatizing effect in relation to the grains 4.

According to Fig. 2, in contrast to Fig. 1, the grains 2 and 4 are unevenly distributed in the foam plastic 1. In the event of a fire in the direction 5 in the portion 6, the grains 4 of nitroamine react faster than the larger grains 2 in section 7. The decisive factor is the greater reaction rate of the grains 4 relative to the grains 2. The spaces 3 between the grains 4 of foam plastic 1, phlegmatize the reaction of the grains 4 in section 6.

In the portion 8 there is a nest formation 9 of grains 4. The grains 4 are in contact with each other and there are no gaps.

There is a faster reaction in section 8 than in section 6.

Claims (7)

~ ,, ..> ._ - .. snww .assm. ~ _ .. @ ..._...-._....__._ .. _. ...__ '_17 .. É..LIÉ _.;.-_ F.- ..... <1 * 460 538 Any pressure peak generated is captured by the surrounding foam 1. Experiments have shown that a suitable mixing process does not achieve or come close to the critical diameter of the nitroamine. (nest formation) can be regulated so that no interplay between phlegmatization and critical diameter 1 overreaction occurs. According to Fig. 3, the grains 4 are provided with a blow-free, solid and dense layer 10 of ethylcellulose. The phlegmatizing layers 10 allow a minimum distance 11 between the grains 4 in a nest formation or accumulation 8. In the nest formation or accumulation 9, the layers 10 in total prevent a pressure peak during the reaction. A normal reaction rate is thus ensured. ¶Ïg? * Nünr Amunuml R fl mmr & xn- læv Yaanß Objects g / amn runs: u¶1HR summa cnxs- nunr vikt-z mbm3 vikc- “z hos energi annat / gr wkÜ% xuüo- K fl g ælmßæm amma mn IE-PS 28 09 279 0,8 80 --- 20 ~ 1,2 3300 16,84 Invention-based drives _ 1ad¿nings_ I 0,8 35 45 20 ~ «0,8 3460 11,03 masses I / 1 ditto l2, * 0.8 25 57 18 ~ 1.0 3600 6.31 ditto 0.8 20 63 17. ~ «0.6 3830 8.42 ditto 0.8 15 69 16 ~ o« 0.5 4030 6.32 ditto IÖà 0.8 10 67 20 N 0.4 3650 6.32 ditto 1 0.3 10 67 20 ~ / 0.3 3650 7.21 In the direction of the arrow 12, the masses show a lively lasting relationship. In the direction of the arrow 13, the masses become narrower. The masses described in Figures 1-3 can be adapted by corresponding selection of parameters to propellant charges for firearms and for pyrotechnic ejector devices. Claims: Propellant mass for fine- to large-caliber tubular firearms and pyrotechnic ejector devices and containing foam plastic with a density of 0.5 - 1.2 g / cm3 and one or more secondary explosives, characterized in that the proportion 460 538 foam plastic, e.g. polyurethane, constitutes 15-25% by weight, that the proportion of secondary explosive constitutes 5-35% by weight and that the proportion of different sized ammonium nitrate grains constitutes 40-80% by weight of the mass, the ammonium nitrate grains 2.0 mm. according to claim 1, has a size of 0.8 - 2. The propellant charge has the characteristic that the secondary explosive consists of a nitroamine and that the surface of the nitroamine moiety amounts to 6-12 cm 2 / g of the mass. Propellant according to Claim 1, characterized in that the secondary explosive has a solid, dense and blow-free layer of plastic or inert material, ranging from 0.3 to 1.0% by weight of the secondary explosive. Propellant mass according to claim 1, characterized in that the secondary explosive consists of a nitroamine and that the nitroamine part consists of grains of a certain size or several different sizes. Propellant mass according to claim 1, k that for a relatively combustible fuel - characterized by propellant with a density of 0.8 g / cm 3, the proportion in the form of a nitroamine 35% by weight at a grain size of constitutes secondary explosive 0.8. mm, the ammonium nitrate content 45% by weight and the foam plastic content 20% by weight of the pulp. Propellant mass according to claim 1, k that for a relatively slowly combustible matter - characterized by propellant mass with a density of 0.8 g / cm 3, the proportion of explosives in the form of a nitroamine 10% by weight is secondary at a grain size of 0 , 4 mm, the ammonium nitrate content 67% by weight and the foam plastic content 20% by weight of the pulp. Propellant mass according to Claim 3, in that the layer (10) consists of PUR (polyurethane). ethylcellulose, lacquer or polyester, and the inert material of graphite, wax or Aerosil. k ä n n e -