RU2253834C1 - Method for manufacture of fragmentation ammunition - Google Patents

Abstract

FIELD: military equipment, applicable for manufacture of fragmentation ammunition to salvo-fire jet-propelled systems.

SUBSTANCE: the claimed method includes production of a shell by deformation and welding, arrangement of finished fragments and fastening to the ammunition body. The shell is molded of plates until a polyhedron is obtained, mainly of a trapezoidal shape with rounded off ribs, and after welding the polyhedron is deformed to a cylindrical shape by grooving, for example, in rolls with localization of deformations in three points, and a multiple, for example two-operation inner grooving, expansion with a decrease of deformation within 1 to 5 per cent, then the shell is placed in a mould, finished fragments are filled in and cast by thermoplastic material, for example, high-density polyethylene, and radial reduction in thickness is simultaneously performed over the entire outer surface, in separate symmetrical sections, for example, at least two, in the plastic area of deformation, and on the rest surface - in the flexible area, at a pressure of 60 to 80 kg/sq.cm during 44 to 46s.

EFFECT: enhanced efficiency of combat use of the ammunition by producing of an irregular stressed state in the shell of the set of finished fragments.

6 cl, 6 dwg

Description

The invention relates to the field of rocketry, and in particular to methods of manufacturing ammunition of rockets of multiple launch rocket systems.

The object of the invention is a method for the manufacture of fragmentation ammunition for warheads of rockets of multiple launch rocket systems with increased combat effectiveness, intended for arming missile and artillery units of the ground forces, and may find application in the field of rocketry.

Ammunition fragmentation of the warheads of rockets of multiple launch rocket systems are mainly used to combat lightly armored vehicles.

An urgent problem in their combat use is to obtain high initial scattering velocities of finished fragments that provide the necessary efficiency.

Various solutions to this problem are known.

A known method of manufacturing a "fragmentation warhead", application of Great Britain No. 1318966, IPC F 42 B 13/48 (Inventions abroad, issue 24, No. 10, 1973), which consists in combining fragments, for example, by soldering, sintering, brazing with copper and zinc or bonding at the point of contact. The warhead also contains a binder made of a material with a lower specific gravity, for example aluminum or plastic.

The effectiveness of combat use is achieved by combining fragments, creating a banding effect.

A known method of manufacturing a “Shrapnel projectile”, UK application No. 1287637, IPC F 42 B 9/02, F 42 B 13/18, “Inventions abroad”, issue 24, No. 17, 1972, in which the block with the finished fragments manufactured as follows. At first, a cage is made in which the finished fragments in the form of balls are poured with synthetic resins.

The necessary speeds are achieved due to the lubrication effect that arises during the melt of resins from the high detonation temperature of the explosive.

Common features with the proposed method of manufacturing ammunition is the presence in the methods of manufacturing shells - analogues of the presence of a binder: plastic, synthetic resins or aluminum.

However, to defeat the armored vehicles, the use of technological methods in analogues that create the effect of “bonding” and lubrication is not enough to obtain the necessary initial expansion speed of the finished fragments.

The closest in technical essence and the achieved technical result to the invention is “Fragmentation projectile and method of its manufacture”, US patent No. 3718091 with a priority of 11/20/68, IPC F 42 B 13/48, abstract magazine “Military equipment and economics” , No. 6, 1974, adopted by the authors for the prototype.

The shell body consists of a glass and a block of finished fragments of a cylindrical shape. The block is made of finished fragments in the form of balls with a polymer binder.

A block of finished fragments is made together with a glass, while the space between the glass and the walls of the mold is filled with finished fragments.

After vibration compaction, the space filled with finished fragments is filled with polyamide or other synthetic resin.

This technical solution uses both the “lubrication” effect and the “bonding” effect.

However, this is not enough to obtain the necessary initial dispersion speed of ready-made fragments of the head of unguided rockets to destroy armored vehicles.

The disadvantage of this method is the lack of technological methods for creating in the block of ready-made fragments and the shell (glass) of a stressed state, contributing to an increase in the initial scattering speed of the finished fragments.

Common signs with the proposed method is the presence of bonding of the finished fragments to each other with an adhesive composition and the connection of the shell with the shell of the ammunition.

In contrast to the prototype, in the proposed method, the shell is molded from sheet metal to obtain a polyhedron, mainly a trapezoidal profile with rounded ribs, and after welding, the polyhedral shape is deformed into a cylindrical calibration, for example, in rollers with localization of deformations in three foci, and multiple, for example, two-operation internal calibration, mainly distribution, with a degree of deformation of 1 ... 5%, then the shell is placed in the mold, the finished fragments are filled in and filled with thermoplastic m material, for example, high density polyethylene, and at the same time carry out its radial compression over the entire outer surface, while in separate symmetrical sections, for example, at least two, in the plastic region of deformation, and on the rest of the surface in elastic, under a pressure of 60 ... 80 kg / cm ² for 44 ... 46 sec.

This allows us to conclude that there is a causal relationship between the totality of the essential features of the claimed technical solution and the achieved technical result.

The objective of the invention is to increase the effectiveness of the combat use of warheads of unguided rockets by creating an uneven stress state in the shell of a block of finished fragments.

The specified technical result is achieved by the fact that in the method of manufacturing fragmentation munition, including obtaining a shell by deformation and welding, placing the finished fragments and fastening to the shell of the munition, the shell is molded from sheet metal until a polyhedron is predominantly trapezoidal with rounded edges, and after welding the polyhedron is deformed , giving it a cylindrical shape by calibration, for example, in rollers with localization of deformations in three foci and multiple, for example, by surgical internal calibration, mainly distribution, with a degree of deformation of 1 ... 5%, then the shell is placed in the mold, the finished fragments are filled in and filled with thermoplastic material, such as high density polyethylene, and at the same time they are radially crimped over the entire outer surface, separate symmetrical sections, for example, at least two, in the plastic region of deformation, and on the rest of the surface in elastic, under a pressure of 60 ... 80 kg / cm ² for 44 ... 46 sec.

A new set of technological methods of the proposed method allows, due to the uneven distribution of internal stresses over the shell cross section, to increase the initial expansion rate of the finished fragments by 12-17%.

The invention is illustrated in the drawing, where Fig. 1 shows the first bending transition, Fig. 2 shows the profile of the shell after the final transition of bending and welding, Fig. 3 shows the profile of the shell after calibration in the rollers, and Fig. 4 is a diagram of the internal calibration of the shell distribution, figure 5 is a cross section of a block of finished fragments, figure 6 is a plot of stresses in the shell of the block.

A method of manufacturing ammunition is as follows. A sheet, for example, steel 08 GOST 19904-74 is cut into blanks. The preforms are subjected to molding at the first transition (Fig. 1) flexible along the edges at an angle α = 80-90 ° and radii R1 and R2, respectively equal to 10-14, 17-21 wall thickness t ₀ at a length h of 45-55 thickness walls (40 mm with a wall thickness of 0.8 mm).

Then the preform is molded at the 2nd transition flexible to obtain a polyhedron with a trapezoidal profile with rounded ribs of different curvature (figure 2) along the radii R1, R2, R3, R4, respectively, equal to 10-14, 17-21, 23-27, 28-33 wall thickness. For example, with a wall thickness of 0.8 mm, the radii R1 = 8-11 mm, R2 = 13-17 mm, R3 = 18-21 mm, R4 = 22-26 mm.

The curvature of the ribs decreases in the direction shown by the arrow in figure 2.

The profile of the mandrels, on which the bending of 1 and 2 transitions is carried out, corresponds to the profile of the semi-finished products (Figs. 1 and 2). In the process of forming a polyhedron in the shell as a result of uneven deformation along the contour in areas with greater curvature - along the edges of the trapezoid with radii R1, R2, R3, R4 (points 0, 2, 3, 5), internal stresses are laid that exceed the stress level by less than curved sections.

The stress level in the areas of the edges of the trapezoid increases in the direction of increasing radius, from R1 to R4 in the direction of the arrow in figure 2.

Then the shell is welded on a semi-automatic welding machine.

After welding, the trapezoidal shape is deformed into a cylindrical calibration with the localization of deformations in three foci on roller rollers.

When calibrating in the rollers get the profile of the shell, close to the cylinder (figure 3).

Local deformation increases the uneven distribution of stresses along the profile of the shell.

In zones 0, 2, 3, 5 (Fig. 3), the level of internal stresses increases.

After that, the shell is subjected to a two-operation internal calibration by distribution with a degree of deformation of 1 ... 5%.

Performing internal calibration distribution with a degree of deformation of 1 ... 5% provides a further increase in the uneven distribution of stresses on the profile of the shell with the growth of the level of stresses in zones 0, 2, 3, 5 (figure 4).

The degree of deformation of 1 ... 5% is optimal from the point of view of ensuring the highest level of stress in these zones.

With a degree of deformation of more than 5%, plastic deformation relieves internal stress in the shell (book “Residual Stresses” by I. A. Berger, Moscow, 1963, p. 206).

When the degree of deformation is less than 1%, the stress level rises to such an extent that it causes distortion of the shape of the shell with the output of geometric dimensions (ovality of diameters, curvature of the generatrix) beyond the limits of permissible deviations.

Then, the shell 6 (see Fig. 5) is placed in the mold 7 on the inner mandrel 8, in the space between the walls of the mold and the shell, the finished fragments 9 are filled, for example, rollers, the mold is installed in an injection molding machine and under pressure 60. ..80 kg / cm ² with an injection time of 44-46 sec. Pour the thermoplastic mass 10, for example high density polyethylene, into the space between the shell and the walls of the mold through the gaps between the finished fragments.

Simultaneously with pouring the thermoplastic mass, radial compression of the shell along the entire outer surface is carried out. On separate symmetrical sections, for example, at least two (1.4), in the plastic region of deformation, and on the rest of the surface, in the elastic.

Plastic deformation is realized (see figure 5) in zones 1 and 4 due to the indentation of these zones of the shell of the thermoplastic mass in two longitudinal grooves of the inner mandrel of the mold.

Elastic deformation is realized on the remaining surface during radial compression of the shell during the pouring of the thermoplastic mass.

The elastic nature of the deformation is ensured by the fact that the shell is mounted on the mandrel of the mold with a small gap not exceeding the elastic deformation of the shell in magnitude.

For example, if the shell wall thickness is 0.8 mm, its diameter is 87.75 mm and the material is steel 08, the clearance is 0.1-0.2 mm.

After removing the block from the mold, the shell remains compressed in the radial direction, the cooled thermoplastic mass.

At the same time, additional internal stresses are created in the shell, which are added to the internal stresses from previous shaping operations.

As a result, the uneven distribution of stresses over the cross section of the shell in the block σ ₀ , σ ₁ , σ ₂ , σ ₃ , σ ₄ , σ ₅ (Fig. 6) increases and reaches values in zones 0, 1, 2, 3, 4, 5, close to yield strength (0.6-0.9 yield strength).

The values of the internal stresses in the shell (in zones 0, 2, 3, 5) increase in the direction of rotation of the munition, shown by the arrow in Fig.6.

Internal stresses in zones 0, 2, 3, 5 in the shell made with the proposed method, measured by the Davydenkov method, were 0.6, respectively; 0.7; 0.8; 0.9 of the yield strength of the material of the shell - steel 08.

For example, if the yield strength of steel was 08-30 kg / mm ^{2, the} internal stresses in zones 0, 2, 3, 5, respectively, were 18, 21, 24, 27 kg / mm ² .

Filling of the thermoplastic material and radial compression of the shell is carried out under a pressure of 60 ... 80 kg / cm ² for 44 ... 46 seconds, which are optimal from the point of view of creating a stress state that provides the maximum initial velocity of the expansion of fragments.

At pressures above 80 kg / cm ² and an injection time of over 46 seconds, over-filling of the finished fragments reduces the combat effectiveness of the ammunition, since when detonating an explosive, fragments of ammunition are formed, including groups of finished fragments.

At a pressure below 60 kg / cm ² and an injection time of less than 44 seconds, the adhesion strength of the finished fragments decreases and the initial expansion speed decreases (by 3 ... 5%).

Thus, the pressure and injection time of the material, respectively 60 ... 80 kg / cm ² and 44 ... 46 sec are optimal to ensure the required characteristics of the munition.

The effectiveness of the combat use of ammunition manufactured by the proposed method increases as a result of the non-uniformity of the destruction of the block during detonation of the explosive due to the uneven distribution of internal stresses over the cross section of the shell.

First of all, the deformation and destruction of the shell occurs in the zone with the highest stress level - in zone 5 (Fig.6).

A compression wave arises in the block in this zone, which acts on the neighboring zones of the block, which increases the pressure in the block and, consequently, the initial expansion velocity of the finished fragments.

The compression wave propagates in the direction of rotation of the ammunition in the direction of the arrow (Fig.6), which creates an additional increase in the initial velocity of the finished fragments.

Multiple launch rockets with fragmentation ammunition manufactured by the proposed method have been extensively tested by bench and flight tests with positive results. At the same time, the initial dispersion rate of the finished fragments increased by 12-17%.

Claims (6)

1. A method of manufacturing a fragmentation munition, including obtaining a shell by deformation and welding, placing the finished fragments and fastening to the shell of the munition, characterized in that the shell is molded from sheet metal to produce a polyhedron with rounded edges, and after welding the polyhedron is deformed, giving it cylindrical shape by calibration and multiple internal calibration by distribution with a degree of deformation of 1-5%, then the shell is placed in the mold, the finished fragments are filled in and the thermoplastics are poured nym pictures and simultaneously its radial compression is performed on the entire outer surface, wherein the reduction in individual symmetric parts carried in the plastic region of deformation, while the rest surface - in the elastic pressure of 60-80 kg / cm ² for 44-46 seconds. 2. The method according to claim 1, characterized in that the polyhedron receive a trapezoidal profile. 3. The method according to claim 1, characterized in that the deformation of the polyhedron by calibration is carried out in rollers with localization of the deformation in three foci. 4. The method according to claim 1, characterized in that the internal distribution calibration is performed in two operations. 5. The method according to claim 1, characterized in that high density polyethylene is used as a thermoplastic material. 6. The method according to claim 1, characterized in that the radial compression in the plastic region is carried out in two sections.

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