RU2267739C1 - Fragmentation envelope of ammunition with preset fragmentation and method for its production - Google Patents

Abstract

FIELD: production of ammunition, in particular, fragmentation warheads of rockets, bombs, shells, mines having envelopes for crushing into fragments.

SUBSTANCE: the fragmentation envelope with a preset fragmentation is made of elongated rods installed between the explosive and the ammunition body, whose fragments are separated in the material uniformity break surfaces transversely positioned and turned relative to one another. The method for manufacture of such a fragmentation envelope consists in installation of rods between the explosive and the ammunition body, which before installation are deformed by twisting in definite intervals of length.

EFFECT: enhanced quality of fragments with a preset energy, with the mass of the fragmentation envelope participating in formation of the affecting elements being unchanged at a simultaneous reduction of the expenditures connected with its production.

19 cl, 10 dwg, 3 ex

Description

The invention relates to ammunition with fragmentation warheads having shells for crushing into fragments or fragments.

Ammunition is known from the technical and patent literature, the shells of which are made of various materials (steel, cast iron, non-ferrous metals, etc.), have smooth or corrugated outer or inner surfaces (see, for example, patents: RU 2171445, F 42 V 12 / 24, 2001; US 5337673, 102-491, 1994; FR 2598214, 1987, Explosion Physics / Ed. By L.P. Orlenko. - 3rd edition, revised. - 2 vol. V.2. - M .: Fizmatlit, 2002 - 656 p.).

At the same time, it is believed that the application of riffles, grooves, notches, etc., helps to approximate the number of fragments generated when the charge is detonated to a predetermined one.

Flutes, grooves, etc. are applied to the shell by various methods of metal forming, mechanical processing, laser, electron beam processing, etc.

It is also believed that ammunition whose shells on the inner surface have a network of rhombic corrugations that do not coincide with the longitudinal direction of plastic deformation of rod and tube semi-products serving as blanks for processing into shells of ammunition (described in patents SU 473335, В 21 С 37/20, 1975; US, 102-67, No. 3566794 dated 02.03.71, 4068590 dated 17.01.78, 3820464 dated 06.28.74).

The disadvantages of these ammunition and methods of manufacturing such shells are the high complexity and capital intensity of their manufacture on special equipment, the instability of the technology associated with the instability of the linear-angular parameters of the shells.

These disadvantages are reduced by the use of a core shell (US patent No. 4216720, 102-67 12.08.80), obtained by installing separate rods, with the formation of a dense row. When this warhead is detonated, elongated fragments are formed with a ratio of length to characteristic diameter of about 28: 1.

Despite the measures to eliminate the tumbling of the rods, the use of such a warhead is fraught with a number of technical difficulties in optimizing the fragmentation effect, which can be achieved by dividing the rod into fragments.

Known fragmentation shell at the application of the United States, H 1047 dated May 5, 1992, NKI 102/496, adopted as a prototype, consisting of unconnected and installed between the explosive and the munition shell of elongated rods. Mentioned rods are divided into separate fragments using cuts made around the perimeter of the rod.

These cuts (grooves, grooves) lead to the loss of mass of material involved in the formation of fragments, and the warhead made of such rods becomes less effective due to the loss of mass by the amount per groove or groove volume multiplied by the density of the rod material .

The use of notches or grooves around the perimeter of the rod for the formation of individual fragments does not always ensure that the required number of slaughter fragments of a certain mass and size are obtained when undermining. during explosive loading, the separation of the rod into grooves and grooves may not occur due to the peculiarities of the wave processes in the fragmentation shell, especially in the contact “grinding” zone bordering the explosive (BB). The difficult to determine balance of the elastic energy reserve in the rod and the energy spent on destruction, depending on the scale factor, is an obstacle in achieving the optimal fragmentation effect.

Of great importance are the fracture (or separation) surfaces of fragments, the topography of which depends on the method of applying grooves, grooves, flutes, etc. to the rod, while the hub of the destruction of a fragmentation shell or rod is considered to be the junction of two surfaces formed by a tool for applying grooves, grooves, flutes, etc., the depth of which, as is customary in practice and consistent with the theory of predetermined crushing, is 0.25-0.55 of the wall thickness for the case of a flat or tubular workpiece (RF patent No. 2171445, 2000).

In the middle zone of the rod, the continuity of which is not broken, the explosion causes internal cracks and pores as a result of the action of rarefaction waves, and the rupture cavities are oriented mainly in the radial direction (Explosion Physics / Ed. By L.P. Orlenko. - Ed. 3rd , - in 2 vols. T.2: Fizmatlit 2002, - 656 p. Page 81). In the process of explosive expansion, the tubular shell is destroyed with the formation of cracks located along the axis. In the case of explosive expansion of the core fragmentation shell, each of the rods undergoes bending deformation, and tensile deformations prevail in the middle part of the rod. In this case, stresses resulting from the action of explosive loading lead to deformations exceeding the plasticity resource, which in turn leads to loss of continuity of the core material.

The profile and dimensions of grooves, grooves, etc., deposited on the rod are of key importance for the transition of deformations of the middle part of the rod from bending to tensile strain. In this case, the energy consumption for fragmentation is directly proportional to bending (they are the smaller, the smaller the bending of the rod).

With a decrease in the width of the grooves, notches, etc., the conditions for the separation of the rod into fragments improve, while it is important in the initial workpiece to maintain the continuity of the material in the area adjacent to the axis of the rod. This ensures the manufacturability of the assembly of fragmentation shells.

Thus, the main drawback of such fragmentation shells is the loss of mass of material per volume of grooves, grooves, corrugations, etc., which is not involved, figuratively speaking, in fragmentation “movement”.

A known method of manufacturing a fragmentation shell, adopted for the prototype according to the application of the United States, H 1047 dated May 5, 1992, NCI 102/496, in which the fragmentation shell is formed by installing separate rods, divided into separate fragments.

The rod can be made of two or more materials, has cuts so that under the action of the load during the explosion it is divided into fragments of a given shape and size. Materials for the manufacture of rods are selected so that two or more damage mechanisms are combined in one fragment. If desired, the rod can be divided into segments containing liquid formulations. The manufacturing process of these rods involving mechanical processing, extrusion, drawing, as well as powder metallurgy methods is extremely complicated and expensive.

The variety of cross-sectional shapes and proposed materials for the manufacture of rods exacerbate these circumstances. The use of tungsten, zirconium, titanium, and other materials proposed in the application of the USA, N 1047 dated May 5, 1992, requires the development of special technologies, and the use of depleted uranium for the manufacture of rods is far from an environmentally harmless event.

The use of powder metallurgy methods for the manufacture of fragmentation rods for this application is controversial, because the efficiency of dividing the rod into fragments according to given grooves is low and depends on the intensity of the explosive load, the initiation point, and many other factors that are not amenable to modeling even with the use of modern computers. For powder materials, including specified in the application (mish metal), the fracture toughness index is an almost indefinite value under wave loading. In this case, the separation of the rod into fragments, as shown in Fig. 3c or 3B (see application US H 1047), does not occur, and the probability of its destruction before separation into fragments increases significantly, which leads to a decrease in the number of slaughter fragments.

The use of the mentioned materials (tungsten, zirconium, titanium, depleted uranium) increases production costs and calls into question the consumer properties of ammunition.

Thus, according to the known method, the manufacture of rods for a number of the proposed materials is unreasonably expensive, which makes the ammunition uncompetitive.

The problem solved by the claimed invention is to increase the efficiency of the fragmentation shell by increasing the number of fragments with a given energy while reducing the cost of its manufacture.

A single technical result consists in increasing the number of killer fragments while maintaining the mass of the fragmentation shell involved in the formation of damaging elements while reducing the cost of its manufacture.

This is achieved by the fact that the fragmentation shell with a given fragmentation is made of rods that are not connected to each other and are installed between the explosive and the ammunition body, consisting of fragments that are separated along the discontinuity surfaces of the gap of the material of the rod.

To achieve the greatest effect, the cross-sectional area of the neck connecting the individual fragments of the rod can be performed in the range from 0.1 to 0.9 of the cross-sectional area of the rod, and the distance (gap) between the individual fragments of the rod can be close to the characteristic grain size rod material.

The power of the warhead is determined by the energy of the detonation processes, the geometric dimensions of the shell, as well as the density, plastic properties, hardness of the material used for the core of the fragmentation shell.

Therefore, in a particular embodiment of the shell, in order to ensure greater penetration of the fragments, the hardness of the surface layer of the rods can be made larger than the hardness in its middle.

A characteristic feature of fragments of shear origin is the presence of a sharp cutting edge in them. Providing high hardness of the surface layer of the rod is ensured, the radius at the apex of the rib is up to a few micrometer units.

In embodiments of the invention (p. 8 ÷ p. 11 of the formula), optimal filling of the space (volume) intended for the fragmentation shell is provided. Therefore, the rods used for the shell are installed in one, two or more rows. In cross section, the rods represent convex figures:

- square or rectangle,

- triangle

- hexagon

- a rhombus.

Moreover, to fulfill the requirement to expand the spectrum of given fragments, combinations of a square and a triangular profile, a rhombic and a triangular, a hexagonal and a triangular, etc. are possible.

The mentioned distinguishing features determine the development of a new method for manufacturing a fragmentation shell with a given fragmentation (Claim 12 to Clause 19 of the claims), which consists in the fact that the fragment shell is formed by installing separate rods between the explosive and the ammunition body, while the rods are deformed by torsion before installation at certain intervals of its length. Fragments of the rod are obtained by torsion deformation at certain intervals of its length with the formation of zones of uneven values of shear deformations, leading to loss of continuity of the material of the rod.

For the best implementation of the method, the deformation zone is localized in the layer crossing the rod.

Torsion (as well as pure shear) allows one to localize the deformation zone to values approaching the characteristic grain sizes of the core material.

Reducing the locally deformed volume of the material during torsion of the rod is achieved by technological methods, which include the availability of various clamping systems and rotations of these clamping devices relative to each other in equipment and accessories. In order to achieve stable shear deformation, for example, in square rods, it is necessary to provide at least a bar clamp on both sides with subsequent rotation of the clamps relative to each other.

The development of local twisting in a zone perpendicular to the axis is predetermined by the unevenness of the deformed state but the cross section of the rod. In this case, a stress state occurs in the center of the rod, due to which the central volume of the metal expires along the axis with elongation of the rod.

Returning to the question of the formation of the aforementioned topography of the surfaces of discontinuity or fracture (separation) of fragments, we note that the purity of these surfaces depends on how much it is possible to avoid decay of a single deformation zone and to localize it to the minimum values.

When torsion, for example, of cylindrical rods in the surface layers, stresses of maximum magnitude arise:

, где φ - угол кручения, r и l - радиус и длина образца.

where φ is the torsion angle, r and l are the radius and length of the sample.

Reducing the length of the deformable (curled) sample by technological methods, i.e. bringing the denominator closer to the minimum values, we provide a radial localization of the deformation, at which local twisting of the sample occurs in the region perpendicular to its axis, as a result of the fact that shear stresses quickly overcome the tensile strength of the rod material with the transition of the deformation zone to the plastic flow region with subsequent loss of continuity. The same plastic deformation affects the characteristics of the discontinuity surface of the material as a result of the movement of the formed crack and its branching.

The microrelief of the resulting tearing continuity surface during torsion differs significantly from the surface treated with a blade or some other tool.

The branching of a crack depends on the material of the rod, its structural characteristics, texture, defects, etc.

Depending on the material of the rod and the geometric shape of its cross section, the angle of relative displacement of adjacent fragments of the rod when turning relative to each other and adjacent to the deformation layer is chosen to ensure the loss of continuity of the material of the rod on an area from 0.1 to 0.9 of the cross-sectional area.

For example, plastic deformation by torsion of square rods from low- and medium-carbon steel in the delivery state and heat-treated (annealing) was investigated. For this, the loss of continuity was determined by comparing the areas of the remaining neck connecting the neighboring fragments with the cross-sectional area of the rod after breaking in a special device.

With relatively stable values of the energy required to split the samples with different strengths and hardness, it was found that the ratio of these areas can be from 0.1 for plastic annealed samples and up to 0.78 for cured, hard. The appropriate technological methods have achieved a situation in which the ratio mentioned reaches 0.9 for hexagonal rods.

The torsion angle can be 360 ° / n, where n is the number of faces of the rod.

Torsion can be performed in two stages, twisting the rods first in one and then in the other direction at the same angle. For example, when practicing the method of manufacturing rods with a triangular, hexagonal and rhombic profile, torsion was performed in two stages - first in one direction and then in the other at the same angle.

In order to obtain fragments with the mentioned sharp cutting ribs and to increase the hardness of the surface layer of rods of low carbon steels, as well as to ensure the safety of the fragment during explosive loading, the rods after torsion deformation can be cemented and then quenched. At the same time, it makes no sense to cement to a depth greater than 0.3 of the thickness of the rod, and the minimum cementation depth should not be less than 0.1 of the thickness, which ensures the presence of a martensite structure on the surface and troostite in the core of the samples during subsequent quenching and tempering.

The invention is illustrated by drawings, which depict:

In Fig.1 - fragmentation shell made of rods;

In Fig.2 - the rod, previously divided into fragments along the transverse-spaced and rotated relative to each other tearing surfaces of the material;

Figure 3 is a fragment of a fragmentation shell with the installation of the rods in two or more rows;

On figa, figb, figv - longitudinal sections of the rods with grooves, grooves and tear surfaces of the continuity of the material;

On figa, figb, figv - illustration of the process of deformation and separation of the rod into fragments;

Figure 6 is an external view of a longitudinal section of a rod with discontinuities after cementation;

7 is an external view of a cross section of a fragment after cementation;

On Fig - microsection in the longitudinal section of the rod at the place of discontinuity of the material continuity.

In Fig.9 and Fig.10 - tool blocks.

The fragmentation shell of an ammunition with a given fragmentation consists of rods 3 not connected to one another and installed between the explosive 1 and the ammunition body 2, divided into fragments 4 along the discontinuity surfaces 5 of the rod material, which are discontinuous and rotated relative to each other. Moreover, the cross-sectional area of the neck S connecting the individual fragments 4 is performed in the range from 0.1 to 0.9 of the cross-sectional area of the rod 3, and the distance h between the individual fragments 4 is close to the characteristic grain size 6 (Fig. 8 ) rod material 3.

The fragmentation shell works as follows: when the explosive 1 is blown up (Fig. 1), the shell 2 expands, and each of the rods 3 undergoes the said bending deformation, and tensile deformations prevail in the middle part of the rod 3.

As a result of the explosive load, the deformation in the middle part of the rod 3 exceeds the plasticity resource of the material, which leads to the final loss of continuity of the rod material along the mentioned surfaces 5 (Fig. 2), ensuring the separation of the rod 3 into fragments according to the scheme of Fig. 5c.

In the case of detonation of a fragmentation shell made according to the scheme of Fig. 3 with the installation of rods 3 of different profiles, additional fragmentation of the munition case 2 (Fig. 3) occurs along the contact lines of the vertices of the triangular rods 3 with the inner surface of the munition case 2, which ensures an increase in the number of fragments.

The proposed method of manufacturing a fragmentation shell with a given fragmentation, consisting of an ammunition body 2 (Fig. 1 or Fig. 3) and rods 3, is carried out by assembly (installation) between the explosive 1 and the body 2 of the individual rods 3, previously subjected to torsion deformation on the press in special device at certain intervals of its length.

A special device is a tool block with a movable 7 (Fig. 9 and Fig. 10) and a stationary clip 8, made in the form of, for example, four-petal collets.

The movable holder 7 is connected by a lever system to the press slider, during the reciprocating movement of which the holder 7 is rotated with the fragment 4 (Fig. 2) relative to the stationary holder 8 with a fixed adjacent fragment.

In this case, the fragments are twisted relative to each other with loss of continuity of the material of the rod along the surfaces of the gap 5, perpendicular to the axis of the rod.

After the technological operation of torsion, the rods (in the case of their manufacture from mild steels) were subjected to cementation, the depth of 9 (Fig.6 and Fig.7) which was set in the range from 0.1 to 0.3 of the thickness of the rod.

Example 1

In the manufacture of the fragmentation shell, rods of steel of square section (the side of the square - 7 mm) were used. The rods were subjected to torsional deformation at equal intervals of length - 8 mm in the tool block (Fig. 9) with two clips - movable 7 and fixed 8, made in the form of four-petal collets. One end of the rod was fixed in a stationary holder 8, and the other in a movable 7, connected by a lever system with a press slider.

During the reciprocating movement of the slide, the movable cage was rotated together with the core fragment fixed in it by an angle of 90 °.

After that, the collets were unclenched and the rod was fed in the axial direction by 8 mm. When repeating these operations, rods of various lengths from 80 mm to 400 mm were obtained, consisting of fragments 8 mm long, rotated 90 ° relative to each other and interconnected in the central part along the longitudinal axis of the rod. The resulting rods were installed between the explosive and the shell of the ammunition.

Example 2

A fragmentation shell was made from steel rods of a triangular section, the side of the triangle was 10 mm. For these rods, three-petal collets were used according to the scheme described in Example 1. One end of the rod was fixed in a stationary holder, and the other in a movable, connected lever system with a press slider, during the reciprocating movement of which the movable holder was rotated by an angle of 30 ° C subsequent reverse rotation to 0 °. The length of the obtained fragments is 10 mm. The length of the obtained rods is from 100 mm to 400 mm. The resulting rods were installed between the explosive and the shell of the ammunition, forming a fragmentation shell.

Example 3

A fragmentation shell was made of square rods (the side of the square was 8 mm). Steel rods were subjected to torsional deformation at the same length intervals of 8 mm in the tool block (Fig. 10) with two clips - movable 7 and fixed 8, each of which is made in the form of two metal clamping jaws performing a similar task (clamping the rod and its rotation ) set forth in examples 1 and 2.

The rotation of the movable cage with the rod clamped in it was carried out at an angle of 45 °, followed by a reverse rotation to 0 °. After this deformation, the rods were subjected to cementation followed by quenching according to the existing technology. The resulting rods were installed between the explosive and the shell of the ammunition, forming a fragmentation shell.

The blasting of the fabricated shells in a special target environment with fragments traps showed that they are crushed strictly along the localization zones of deformation or, what is the same, along the surfaces of the discontinuity of the core material. In this case, the damaging elements correspond to a given fragmentation in size, shape and weight.

Claims (19)

1. The fragmentation shell of an ammunition with a given fragmentation, made of rods that are not connected to each other and are installed between the explosive and the ammunition body, characterized in that each rod is divided into fragments along the discontinuity surfaces of the gap of the material of the rod. 2. The fragmentation shell according to claim 1, characterized in that the cross-sectional area of the neck connecting the individual fragments of the rod is made in the range from 0.1 to 0.9 of the cross-sectional area of the rod. 3. The fragmentation shell according to claim 1 or 2, characterized in that the distance between the individual fragments of the rod is a value closer to the characteristic grain size of the material of the rod. 4. The fragmentation shell according to claim 1 or 2, characterized in that the hardness of the surface layer of the rods is made larger than the hardness in its middle. 5. The fragmentation shell according to claim 3, characterized in that the hardness of the surface layer of the rods is made larger than the hardness in its middle. 6. The fragmentation shell according to claim 4, characterized in that the thickness of the harder surface layer is from 0.1 to 0.3 of the thickness of the rod. 7. The fragmentation shell according to claim 5, characterized in that the thickness of the harder surface layer is from 0.1 to 0.3 of the thickness of the rod. 8. The fragmentation shell according to claim 1, characterized in that the rods are installed in two or more rows. 9. The fragmentation shell according to claim 8, characterized in that the rods of the outer row have a triangular profile. 10. The fragmentation shell according to claim 8, characterized in that the rods of the outer row have a hexagonal profile. 11. The fragmentation shell according to claim 8, characterized in that the rods of the outer row have a rhombic profile. 12. A method of manufacturing a fragmentation shell with a given fragmentation, in which a fragmentation shell is formed by installing separate rods between the explosive and the ammunition body, characterized in that the rods are deformed by torsion at certain intervals of its length before installation. 13. The method according to p. 12, characterized in that the deformation zone is localized in the layer crossing the rod. 14. The method according to p. 12 or 13, characterized in that the angle of relative displacement of adjacent fragments of the rod when turning relative to each other and adjacent to the deformation layer is chosen to ensure the loss of continuity of the material of the rod on the area from 0.1 to 0.9 of the cross-sectional area of the rod . 15. The method according to p. 12 or 13, characterized in that the torsion angle is equal to 360 ° / n, where n is the number of faces of the rod. 16. The method according to p. 12 or 13, characterized in that the torsion is performed in two stages, twisting the fragments of the rod first in one direction and then in the other direction at the same angle. 17. The method according to 14, characterized in that the torsion is performed in two stages, twisting the fragments of the rod first in one direction and then in the other direction at the same angle. 18. The method according to p. 15, characterized in that the torsion is performed in two stages, twisting the fragments of the rod first in one direction, and then in the other direction at the same angle. 19. The method according to p. 12 or 13, characterized in that the rods are made of mild steel, and after deformation are subjected to cementation with subsequent hardening.

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