RU2409803C1 - Fragmentation ammunition casing - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: casing of fragmentation ammunition includes cylindrical cover on inner surface of which there is fragmentation grid made from spiral and opposite-directed riffles having the depth of 0.25…0.55 of thickness of the cover wall and forming semi-finished fragments as per the shape of truncated pyramids conjugated with their rhomb-shaped bases, driving band and low-pressure chamber formed by means of bottom connection strap and open backwards in cone shank. Main diagonal of the bases of fragments is oriented relative to the cover within ±15°. Length of the above diagonal exceeds cover wall thickness by 1.5…2.5 times, and length of small diagonal by 1.4…2.0 times. Bottom connection strap on the cover side is equipped in addition with layer of semi-finished fragments formed with cavities with depth of 0.2…0.4 of thickness of bottom connection strap and as per the shape of many-sided pyramids the side edges of which are inclined relative to the plane of connection strap at an angle of 40°…50°. At that, bases have total surface area of not less than 0.22 of surface area of bottom connection strap. Low-pressure chamber has depth of not more than 1.5 of gauge and thickness of its side wall is not more than 0.35 of thickness of bottom connection strap.

EFFECT: increasing efficiency of fragmentation effect of the shell.

3 dwg

Description

The invention relates to fragmentation ammunition with a given crushing of the hull into striking elements of a rational shape, and more particularly to artillery shells, the hull of which has a cylindrical shell with an internal weakening notch in the form of intersecting multi-helical spiral grooves (corrugations).

Known artillery shell according to patent RU 2248514 C1, F42B 12/24. The body is made of prefabricated two parts: a thin-walled cylindrical fragmentation shell and an aerodynamic shaft, rigidly interconnected. To crush the shell along its inner surface, uniformly distributed pyramidal fragments formed by the intersection of spiral grooves are made. To improve the shape of the projectile, its tail section is made conical, tapering posteriorly, where a rarefaction chamber open from the bottom of the bottom is formed by means of the bottom bridge, on the walls of which there are through radial slots. The presence in the side wall of the rarefaction chamber of the through radial slots contributes to its crushing during the explosion of the projectile. The design drawback is that during the explosive destruction of the hull with an attached bottom, the latter is separated in the form of a heavy fragment with poor aerodynamics, which reduces the density and area of the fragmentation field.

The closest technical solution to the claimed invention is the shell fragmentation munition according to patent RU 2196294 C1, F42B 12/22. The case is made monolithic, and its cylindrical shell has a grid of semi-finished fragments in the form of truncated rhombic pyramids on the inner surface, formed by two rows of equally distributed spiral riffles of the opposite direction. The tail of the body is made conical and tapering back. An open rarefaction chamber with through radial slots on the walls is made in the tail part from the bottom side. In the case of explosion of the body, its spiral corrugations and through radial slots are sources of nucleation of longitudinal and transverse cracks forming fragments from a cylindrical shell, bottom and walls of the rarefaction chamber.

The noted technical solutions, despite differences in their design, have common disadvantages. First, the fragmentation grid of their cylindrical shells is geometrically determined only by the depth of the grooves. But, as practice shows, this is not the only parameter that ensures high-quality crushing of the shell into a given number of fragments of the required mass.

The development of the characteristics responsible for the explosive destruction of cases with a rhomboid fragmentation grid showed that an important factor affecting the quality of crushing the case is the angle of elevation of the spiral riffles, as well as their circumferential step, which determine the size of the fragments, the inclination of the sides of their rhomboid bases relative to the generatrix of the shell, and consequently, the directions of the three main stress concentrators: spiral, as well as zigzag in the longitudinal and circumferential directions.

The tendency of these stress concentrators to destruction is different and is determined by their orientation with respect to the front of the oblique rarefaction wave that arose when the detonation wave glided along the inner surface of the shell.

It has been established that at angles of elevation of spiral riffles more than 45 ° (rhombs are extended along the generatrix), the formation of longitudinal zigzag and spiral main cracks is easier than the circumferential zigzag main cracks and is accompanied by the partial formation of “saber” fragments from fragments located along the generatrix of the shell. These fragments have a poor aerodynamic shape, which means a small radius of the damaging effect. When the riffle rise angles are less than 45 ° (rhombuses are elongated in the circumferential direction), the formation of longitudinal zigzag main cracks will be the most difficult, as a result of which ineffective group fragments are formed from fragments located along the circumference of the shell.

In addition, when the angles of spiral riffs rise significantly different from 45 ° to a greater or lesser extent, the main zigzag cracks in the transverse and longitudinal directions, respectively, due to the small pitch between the zigzag vertices, have a high fracture resistance. And this leads to the fact that the destruction of the shell passes not only along these grooves, but also directly through the body of the semi-finished fragment, crushing the latter into smaller fractions with a low damaging effect.

Secondly, the analogs do not reflect the influence on the fracture pattern of the fragment sizes determined by the length of the large and small diagonals of their diamond-shaped bases. Tests established that, when the size of the semi-finished fragment is significantly larger than the wall thickness of the shell, the main cracks propagate not only along the rhombic bases of the semi-finished fragments, but also along the fragment itself, destroying it into several parts, which impairs the characteristics of the fragment flow.

The absence in the known technical solutions of the relationship between the basic geometric parameters of the semi-finished fragments and the wall thickness of the shell makes it difficult to refine the shell in terms of ensuring its planned fragmentation.

In addition, the results of the blasting of the shells revealed the insufficient presence of through radial slots in the side wall of the rarefaction chamber to ensure acceptable crushing of the bottom of the shell. The bottom in this case is destroyed only by a few very large and heavy fragments, its separation in the form of one monolithic element is often observed, which is not permissible.

The objective of the invention is to increase the efficiency of fragmentation of the projectile due to the guaranteed crushing of the shell and the bottom of the body with an open rarefaction chamber on the damaging elements of a given shape and mass.

The required technical result is achieved by the fact that in the known shell of fragmentation munition containing a cylindrical shell, on the inner surface of which a fragmentation grid is made of spiral and counter-directed corrugations having a depth of 0.25-0.55 shell wall thickness and forming semi-finished fragments in shape truncated pyramids, conjugated by their rhomboid bases, the leading girdle and the rarefaction chamber in the conical shaft formed by means of the bottom lintel are new:

- the fragments are oriented by a large diagonal of their bases relative to the generatrix of the shell in the limit of ± 15 °;

- the length of the large base diagonal exceeds the wall thickness of the shell by 1.5-2.5 times, and the length of the small diagonal by 1.4-2.0 times;

- the bottom lintel from the shell side is additionally equipped with a layer of semi-finished fragments formed by depressions with a depth of 0.2-0.4 of the thickness of the bottom lintel and in the shape of polyhedral pyramids, the side faces of which are inclined relative to the plane of the lintel at an angle of 40 ° -50 °;

- the base of the depressions have a total area of at least 0.22 of the area of the bottom lintel;

- the rarefaction chamber is made with a depth of not more than 1.5 caliber and has a side wall thickness of not more than 0.35 of the thickness of the bottom lintel.

The invention is illustrated by drawings, which schematically depict:

- figure 1 is a General view of the shell without explosive;

- figure 2 is a section aa in figure 1 in an enlarged view;

- figure 3 is a fragment of the sweep of the shell along its inner surface.

The proposed shell fragmentation munition contains a cylindrical shell 1, consisting of a thickness 2 of the bearing wall 3 and protruding into the layer of semi-finished fragments 4 in the form of truncated rhombic pyramids. The height of the semi-finished fragments 4 is equal to the depth of the grooves 5 and is 0.25-0.55 of the wall thickness of the shell 2. On the shell 1, a lead girdle 6 is made, a rarefaction chamber 9 is formed in the tapered shank 7 tapering rearwardly by means of a bottom bridge 8.

For high-quality structuring of mass fractions of fragments formed from the tail of the body, a layer of semi-finished fragments 10 with a thickness of 0.2-0.4 of its thickness 11 is made in the bottom lintel 8 from the side of the shell 11. These semi-finished fragments are formed using recesses 12 in the form of polyhedral pyramids , the side faces of which are inclined relative to the jumper plane at an angle of 13.

In an explosion, the shell 1 of the shell of the shell, dynamically loaded from the inside with detonation products, begins to intensively collapse in the radial and axial directions. At the same time, along the riffles, which are the localizers of destruction, a system of multidirectional spiral 14, longitudinal zigzag 15 and transverse zigzag 16 main cracks arises, starting from the location of the source of initiation of the explosive. The unhindered propagation of these cracks, which are the source of the formation of group “saber-like” fragments, is hampered by the fact that the riffles are not located along the shell texture, but at a certain angle to the front of the detonation wave and have a counter direction with the intersection at the nodal points of the 17 fragmentation grid. When the shell is destroyed with rhomboid fragments elongated along its generatrix in spiral 14 and longitudinal 15 zigzag riffles, cracks form faster than in transverse 16 zigzag riffles. This is due to the fact that the step 18 of the transverse zigzag grooves 16 is less than the step 19 of the longitudinal 15 zigzag grooves, and therefore they also have a higher fracture resistance. This excludes the primary “triggering” of transverse zigzag cracks, which means the formation of small fragments.

Before the destruction of the shell 1 of the shell of the shell has a barrel-shaped shape and is a complex construction. Under these conditions, a restriction depending on the thickness of the wall of the shell, the size of the semi-finished fragment in the longitudinal and transverse directions is mandatory, as this eliminates its excessive deflection in the radial direction and the formation of microcracks directly in it, which undesirably destroy the integrity of the fragment.

Simultaneously with the explosive fragmentation of the shell 1, the bottom jumper 8 is planned to be destroyed, followed by the “skirt” of the rarefaction chamber 9. This is mainly due to equipping the bottom jumper 8 with fracture locators in the form of recesses 12. Due to the fact that the recesses 12 are made in the form of multifaceted pyramids, in the explosion, their adjacent side faces, similar to shell riffles, perform the functions of a gas wedge for detonation products. The result of the interaction of detonation products with the inclined side faces of the recesses 12 is an organized crushing of the bottom bridge 8 along the ribs of each of the recesses. The flow of multidirectional cracks formed in this case captures the side wall of the rarefaction chamber 9 and breaks it into a number of fragments of arbitrary shape and acceptable mass.

These technical solutions are implemented in a grenade full-time 30-mm GPD-30 shot of increased efficiency. The execution of the grenade body with the following nominal geometric parameters: shell wall thickness - 3.72 mm; depth of corrugations - 1.15 mm; the length of the large and small diagonal of the semi-finished fragments, respectively - 7.5 and 4.3 mm; the thickness of the layer of semi-finished fragments in the bottom lintel - 1.4 mm; thickness of the bottom lintel - 5 mm; the shape of nine recesses in the bottom lintel is a tetrahedral truncated pyramid with an angle of inclination of the side faces relative to the plane of the bottom lintel 45 °; the total base area of the nine pyramidal depressions is 0.24 of the area of the bottom lintel; the depth of the rarefaction chamber is 0.45 caliber; the thickness of the side wall of the rarefaction chamber - 1.3 mm ensured the separation of the shell during the explosion without the formation of conglomerates in the form of separate couplers of semi-finished fragments and a small number of fragments weighing less than 0.25 g.

The results of rational crushing of the GPD-30 grenade body were confirmed by the act of field tests in military unit 33491.

Similar results were obtained with explosions in the armored chamber of the experimental grenade bodies of the 57-mm VOF-57 rounds manufactured in accordance with the proposed technical solutions. This fact is confirmed by a number of official reports of FSUE GosNII Kristall and FSUE SRI Geodesy, according to which fragmentation occurs almost in the planned mode.

The question of the application of the above developments in a 100-mm shell of a regular shot ZUOF17 is being considered.

The positive results of comprehensive research and full-scale tests of 30- and 57-mm grenades guarantee the creation of highly effective fragmentation shells and other calibers.

Information sources

1. RF patent №2248514, IPC F42B 12/24, publ.

2. RF patent No. 2196294, IPC F42B 12/22, publ. - prototype.

Claims (1)

Shell fragmentation munition containing a cylindrical shell, on the inner surface of which is made a fragmentation grid of spiral and counter-directed corrugations having a depth of 0.25 ... 0.55 shell wall thickness and forming semi-finished fragments in the shape of truncated pyramids, paired with their diamond-shaped bases, leading the girdle and the rarefaction chamber open in the conical shank formed by means of the bottom bridge, characterized in that the fragments are oriented by a large diagonal of their relative bases of the generatrix of the shell in the range of ± 15 °, while the length of this diagonal exceeds the wall thickness of the shell by 1.5 ... 2.5 times, and the length of the small diagonal by 1.4 ... 2.0 times, the bottom bridge on the side of the shell is additionally equipped a layer of semi-finished fragments formed by depressions with a depth of 0.2 ... 0.4 of the thickness of the bottom lintel and the shape of polyhedral pyramids, the side faces of which are inclined relative to the plane of the lintel at an angle of 40 ... 50 °, and the bases have a total area of at least 0.22 area of the bottom lintel while the vacuum chamber is made in depth e 1.5 caliber and has a side wall thickness of not more than 0.35 the thickness of the bottom web.

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