Plastic cartridge case for artillery shot

Abstract

The invention relates to a plastic cartridge case for artillery shells, which can be used in the production of ammunition, in particular in the design of composite and mono block artillery cases with a plastic body, in particular for artillery shells with separate or single loading, as well as for ammunition for small arms. A plastic cartridge case for artillery shots consists of a metal bottom in the form of a disk, fixedly connected to a plastic body, in which a cylindrical stepped metal body is mounted, in the inner space of which an ignition capsule is mounted by means of a threaded connection, the metal bottom (4) being filled with a recess, in which the plastic body (2) is placed, the stepped metal body (1), in the front part of which a tube (7) is fixedly mounted, oriented along the axis of the plastic body, with radially oriented holes (7a) formed along its length, and an incendiary charge (8) is placed inside it.

Description

PLASTIC CARTRIDGE CASE FOR ARTILLERY SHOTField of the invention

[0001] The invention relates to a plastic cartridge case for artillery shells, which can be applied in the manufacture of ammunition, in particular in the design of composite and mono block artillery cartridge cases with a plastic body, specifically for artillery shells with separate-loading or unitary- loading systems, as well as for small arms ammunition.Background of the invention

[0002] An artillery cartridge case is known from Bulgarian Patent No. 67608 Bl, applicable for shells with separate or unitary loading, consisting of a metal base and a plastic body fixedly attached to it. Centrally on the inner surface of the metal base, a cylindrically shaped projection is formed, in which a stepped hole is made. Inside the base of the plastic body, a pressure-retaining ring is placed, and between the outer side of the bottom of the plastic body and the inner part of the metal base, a sealing gasket is inserted.

[0003] A known composite artillery cartridge case from US Patent No. 2564695 is applicable for separate-loading shells. The cartridge case body is attached to the base by a sheet of plastic with slotted ends. To join the body with the base, channels are formed on its inner surface.

[0004] A disadvantage of this solution, as shown in practice, is the insufficient strength of the connection between the body and the base, which becomes apparent during firing with charges developing pressures greater than 2000 kg / cm2. When powder gases leak, or when the body and the base separate, this flaw prevents the extraction (ejection / removal) of the entire cartridge case. This is due to the difficulty of technically achieving the necessary geometric precision in the “body-base” connection, resulting in the moistening of the powder charge during long-term storage, which leads to deterioration in the ballistic characteristics of the charge.

[0005] US Patent Publication No. 3170401 is also known, which describes a composite cartridge case consisting of a plastic body, a plastic sealing ring, and a fastener. The described case is not sufficiently effective when used under conditions such as low temperatures (-50°C) and moderate pressures between 1500 kgf / cm2and 3000 kgf / cm2, as under these conditions, proper sealing of the powder gases cannot be ensured.

[0006] US Patent Publication No. 3026802 discloses the construction of a composite artillery cartridge case that ensures reliable connection of its elements — plastic body, metal base, metal pressure ring, and primer. The structural strength is provided by a ring formed on the outer surface of the capsule walls.

[0007] During firing under increased powder gas pressure from a semi-automatic gun, as well as at small barrel elevation angles when the energy of the gun's breech wedge reaches its peak, the strength of the described cartridge case construction proves to be insufficient. In practice, there have been cases where the body rotates relative to the base or the case disassembles, leading to incomplete extraction of the case. At the same time, this insufficient structural strength allows leakage of powder gases, whose high pressure and temperature can damage the firing mechanism of the gun.

[0008] An artillery cartridge case is known from RU 2148241, consisting of a metal base fixedly connected to a plastic body, a metal bottom plate, a fastening ring, a nut, and a sealing pad. Centrally in the bottom of the plastic body, a cylindrically shaped protrusion is formed with a stepped hole for mounting a primer, where the lower part of the plastic body is located inside the metal base. A sealing fastening ring is placed over the bottom of the plastic body, pressed by a nut fixed on the protruding part of the metal base, and a sealing pad is placed between the bottom of the plastic body and the lower surface of the fastening ring.

[0009] The described elements and their mutual arrangement ensure the hermetic sealing of the connection between the metal base and the plastic body, as well as maintain the strength of the connection between the plastic body and the metal base, which is of particular importance when using the plastic cartridge case under firing conditions with increased propellant gas pressure from semi-automatic guns at small barrel elevation angles. The described cartridge case is suitable primarily for use in artillery systems with separate-loading, medium caliber, and especially for howitzers.Summary of the invention

[0010] Given the state of the art in the examined field, the aim of the invention is to propose a design of a plastic cartridge case for assembling artillery shells with unitary and separate loading, suitable for howitzer and artillery systems with high ballistic performance and working pressure exceeding 500 MPa, ensuring guaranteed strength of the plastic cartridge case body, reliableignition of the propellant charge, and preservation of the integrity of the cartridge case construction during firing and after extraction.

[0011] Another aim of the invention is to propose a plastic cartridge case that ensures the extraction of the fired case, as well as reliable sealing (obturation) of the propellant gases during firing, including the possibility for repeated use of the plastic cartridge case. A further aim of the invention is to propose a design of a plastic cartridge case for assembling artillery shells with unitary and separate loading, which provides for the reliable achievement and maintenance of the appropriate speed and pressure parameters through the use of a propellant charge with suitable geometric parameters and energetic characteristics.

[0012] The aim is achieved with a plastic cartridge case for artillery shells, particularly for systems with separate and unitary loading, consisting of a metal base in the form of a disc, fixedly connected to a plastic body. Centrally in the metal base, a stepped hole is formed, in which a stepshaped metal element is mounted. Inside this element, a primer is mounted via a threaded connection.

[0013] Inside the plastic body, a threaded pressure ring is housed, which is fixedly connected to the step-shaped metal element where the primer is mounted, and between the metal base and the plastic body, a hermetically sealing rubber pad is placed. The inner volume of the plastic body contains the propellant charge.

[0014] According to the invention, the metal base has a recess in which the plastic body is placed, and the protruding part of the step-shaped metal element includes a threaded sector with a maximum thread diameter, into which the threaded pressure ring is mounted. The diameter of the stepped hole intended for mounting the primer is within the range of 0.42 mm to 0.68 mm of the minimum diameter of the protruding threaded part of the step-shaped metal element. A tube is fixedly mounted to its front part, aligned with the axis of the plastic body. Along the length of the tube, radially oriented holes are made, and inside it is a primer charge. A metal ring is positioned in the front cylindrical part of the plastic cartridge case.

[0015] The metal bottom is shaped as a metal disk, with a centrally formed stepped opening, with a recess, with a depth h4 and a radius of curvature DI .

[0016] The thickness of the metal disk is equal to 0.6 to 0.8 mm, of the thickness of the bottom of the plastic housing.

[0017] According to a preferred embodiment of the invention, the plastic housing is made as a single element.

[0018] The plastic housing is made of plastic, the composition of which contains an antistatic substance, in an amount of 3 to 5% of the total weight of the plastic housing and a UV additive, in an amount of not less than 2.5% relative to the total weight of the plastic housing. It is preferable that the antistatic substance is graphite.

[0019] In a variant embodiment of the plastic cartridge case, a protective zinc-phosphate or chromium coating is applied to the metal parts, with a thickness of not less than 7 mum.

[0020] In a preferred embodiment of the plastic cartridge case, pyroxylin gunpowder is used for the propellant charge.

[0021] The length of the radially perforated tube is at least two-thirds 2 / 3 of the height of the plastic housing and is located along the axis of the plastic housing structure of the cartridge case.

[0022] The radial holes are provided along the entire length of the tube, arranged in a circle, spiral or staggered.

[0023] According to another variant embodiment of the plastic cartridge case, black smoke gunpowder is placed as an incendiary charge located in the inner space of the radially perforated tube.

[0024] It is suitable for the metal ring to be provided with a wall thickness of 1.2 to 2.0 mm.

[0025] According to a preferred embodiment of the plastic cartridge case, the subject of the invention, in the front cylindrical part of the plastic cartridge case is formed an internal spherical rim, with a diameter, with a radius of curvature R3 and a diameter - smaller than the diameter of the channel in the bottom of the projectile.

[0026] According to a preferred embodiment of the plastic cartridge case, the subject of the utility model, the outer diameter of the pressing threaded ring refers to the diameter of the metal bottom under the flange and is 0.66 to 0.87 mm, and its thickness is equal to 0.35 ... 0.7 mm of the thickness of the metal bottom.

[0027] The pressing threaded ring is made with a central threaded hole, with a size corresponding to the threaded sector, made along the convex cylindrical surface of the stepped metal cylindrical body, as at least two technological holes are made radially in the pressing threaded ring.

[0028] Preferably, the outer radius, fitting the forming side surface of the plastic housing with its bottom is made with a radius of 0.6 - 1.3 mm from the radius of the metal bottom.

[0029] It is preferable that the inner radius of the bottom of the plastic housing is made with a radius of 0.8 - 1.2 mm, relative to the outer radius it is made within the range of 1.3 to 1.42 mm of the minimum diameter "d" of the thread for screwing the capsule cartridge case, and the diameter of the hole for mounting the capsule cartridge case is made within the range of 0.42 to 0.68 mm of the minimum diameter of the metal stepped-shaped body, with the hole for mounting the tube with radial holes dl equal to 0.45 ... 06 of the diameter D.

[0030] In one variant embodiment of the plastic cartridge case, the pressing threaded ring is made in compliance with the ratio between the outer diameter of the pressing threaded ring to the diameter of the metal bottom 4 and is in the range of 0.66 ... 0.87 mm, and the thickness of the pressing threaded ring is equal to 0.35 ... 0.7 mm of the thickness of the metal bottom.

[0001] The pressing threaded ring for separate cartridge case loading is made with an outer diameter Fl and a thickness h, and has a central threaded hole through which it is mounted to the stepped shaped metal body, in which the igniter capsule is fixedly attached, with at least two, preferably four, technological holes formed radially on the pressing threaded ring.

[0032] In one variant embodiment, the pressure threaded ring is made with an outer diameter F2 equal to 0.8 ... 0.65 of Dl (thread diameter of the pressure threaded ring) and a thickness h, with a central threaded hole with a diameter D 1 , through which it is mounted to a stepped shaped metal body 1 , into which the igniter capsule is screwed, with at least two, preferably four technological holes formed radially on the pressure threaded ring.

[0033] In one variant embodiment of the plastic housing, the radius R of connection of the outer cylindrical surface of the plastic housing with its bottom surface is equal to 0.6 ... 1.2 mm of the inner radius R1 of the metal bottom.

[0034] In one variant embodiment of the body of the plastic cartridge case, an internal arcuate rim is structurally formed at the upper end of the cartridge case, the formed internal diameter being smaller than the diameter D2, whereby the internal arcuate rim has a spherical shape, with a radius R5.

[0035] In one embodiment of the plastic cartridge case, it is appropriate to install an additional pressing threaded ring.

[0036] The proposed design of a plastic cartridge case is distinguished by a high degree of efficiency in technical and technological terms, while simultaneously ensuring guaranteed strength of the plastic cartridge case body, reliability of ignition of the propellant charge and preservation of the integrity of the cartridge case structure during firing and after extraction.

[0037] The proposed design provides reliable sealing, obturation of the gunpowder gases during firing, including the possibility of multiple use of the plastic cartridge case. The plastic cartridge case, the subject of the utility model, is suitable for use in composite plastic cartridge cases for separate cartridge case and unitary loading. It ensures reliable achievement and maintenance of the relevant parameters for speed and pressure by using a propelling powder charge with appropriate geometric parameters and energy characteristics.

[0038] Appropriately selected dimensions of the metal bottom allow assembly of the elements, as a result of which the maximum degree of tightness is ensured and the possibility of leakage and leakage of powder gases is excluded when producing a shot is produced. In addition, to ensure tightness, it is possible to place an additional ring of plastic material and place a hermetic heat- resistant paste. At the same time, the constructive combination of the dimensions of the stepped opening of the metal bottom leads to knocking out of the primer primer cartridge case from the threaded socket, observed when firing from artillery systems with high ballistic characteristics and operating pressure of powder gases greater than 500 MPa.

[0039] For the purpose of achieving maximum characteristics, velocity and pressure of the powder gases in the charging chamber of the firing system and distance of the shots, for example for artillery shots with unitary and separate cartridge charges, pyroxylin powder is used as a propellant charge located in the inner space of the plastic cartridge, in an amount and composition ensuring maximum characteristics of the system and the shot, with a view to achieving the set parameters, distance and grouping of hits and effectiveness at long distances.

[0040] To achieve certain parameters, speed and pressure of the powder gases in the charging chamber of the firing system and the distance of the shots for unitary and separate cartridge charging, a reduced quantity, i.e. variable propellant charge can be used, which in turn means that the propellant charge of pyroxylin gunpowder, located in the inner space of the plastic cartridge, is in a quantity and composition that ensures the desired distance, the specified characteristics of the system and the shot to achieve the set parameters, grouping of hits and efficiency at shorter distances, by changing the amount of propellant charge and the aiming angle of the firing system.

[0041] One of the main requirements for assembled and full-body artillery cartridges with a plastic body is to ensure the strength of the cartridge case when fired, reliable extraction and repeated reuse. The peculiarity of these cartridges is that they are used to complete shots for powerful large- caliber guns operating at significantly high pressures in the barrel bore with separate-case and unitary loading.

[0042] When a shot is fired, under the action of the pressure of the gunpowder gases, the plastic body of the cartridge case plastically deforms, fitting tightly into the charging chamber of the gun, as a result of which a sealing process occurs and preventing the leakage of the gunpowder gases into the gun breech.

[0043] The conducted studies show that the temperature coefficient of linear expansion of the plastic body of the cartridge case is greater than that of the expansion coefficient of the metal. As a result, a design of a composite and full-body plastic cartridge case has been proposed.

[0044] Structurally, the shell body is made with appropriate dimensional ratios in the radial direction, with the wall thickness of the shell being chosen to increase progressively from the frontal part to the bottom of the shell. The reduction in the diameter of the thread in the socket for mounting the primer cartridge case, combined with the significant elastic-plastic radial deformations of the metal bottom, leads to the achievement of maximum pressure in the chamber of the gun barrel. This process is accompanied by leakage (breakthrough) of the gunpowder gases in the gun breech, which is extremely dangerous for the health and life of the combat crew. This results in crushing and shearing of the threads of the thread in the socket for mounting the primer cartridge case, which makes it impossible to reuse fired shells after their renewal. In addition, the pressure of gunpowder gases on the ignition means, falling between the gap between the mirror wedge of the gun bolt, can lead to jamming of the bolt and the impossibility of extracting the fired cartridge case.

[0045] The implementation of the maximum diameter D 11 of the metal bottom, for example, with a size larger by 0.8 mm than the minimum diameter D9 of the metal step body, on the outer surface of the step body, under the action of gunpowder gases, a sharp increase in radial and tangential stresses in the thread area, and to the transition section of the metal step body, and to plastic deformation with the formation of significant ultimate deformations of the metal bottom and, as a consequence, jamming of the bolt.

[0046] The implementation of the minimum diameter of the hole dl in the metal stepped body within the range of 0.22 ... 0.93 mm of the minimum diameter D9, makes it difficult to spread the forcing of fire from the primer igniter to the ejector charge, which causes unevenness of its ignition, accompanied by high pressure of gunpowder gases beyond the permissible limit. This phenomenon leads to an increase in the radial deformation of the walls of the metal stepped body and the charging chamber of the gun, the formation of significant radial tightness between the walls of the bottom and the chamber of the gun and the impossibility of extracting the fired cartridge case. The implementation of the maximum diameter dl of the hole of the metal steppedshaped body, more than 0.93 mm from the minimum diameter D9, causes, at the moment of operation of the primer igniter, destruction of the convex part of the metal stepped-shaped body, which excludes the repeated use of the fired plastic cartridge case, as a result of the uneven distribution of the pressure gradient in the inner surface of the plastic body of the cartridge case for unitary and separate cartridge case loading, and a decrease in the wall thickness of the metal stepped-shaped body.

[0047] The cartridge case body is structurally designed with suitable radial dimensional ratios, with the wall thickness increasing progressively from the front end toward the base. A reduction in the thread diameter of the seat for the primer cartridge case, combined with significant elastic-plastic radial deformations of the metal base, leads to the attainment of maximum pressure in the barrel chamber of the weapon. This process is accompanied by gas leakage (blow-by) into the breech, which is extremely dangerous for the health and life of the gun crew. Additionally, thread crushing and shearing in the primer cartridge case mounting seat may occur, rendering the spent cartridge cases unusable for reloading. The pressure of the propellant gases on the primer device, when caught in the clearance between the breechblock mirror and the weapon’s chamber, may cause jamming of the breech and prevent the extraction of the spent cartridge.

[0048] The implementation of the maximum diameter DI 1 of the metal bottom, for example, with a size larger by 0.8 mm than the minimum diameter D9 of the metal step body, on the outer surface of the step body, under the action of gunpowder gases, a sharp increase in radial and tangential stresses in the thread area, and to the transition section of the metal step body, and to plastic deformation with the formation of significant ultimate deformations of the metal bottom and, as a consequence, wedging of the shutter.

[0049] If the minimum diameter dl of the bore in the stepped metal body is between 0.22 and 0.93 mm of the minimum diameter D9, the propagation of the ignition from the primer to the propellant charge is hindered, resulting in uneven ignition and gas pressure exceeding acceptable limits. This leads to greater radial deformation of the walls of both the stepped metal body and the chamber, causing tight radial interference between the cartridge base and the weapon chamber and preventing extraction of the fired cartridge. If the maximum diameter dl of the bore exceeds 0.93 mm of the minimum diameter D9, it may result in the destruction of the protruding part of the stepped metal body upon primer ignition. This prevents the reuse of the plastic cartridge due to uneven pressure distribution inside the plastic case, and reduces the wall thickness of the stepped metal body.

[0050] The plastic cartridge for unitary and separate-loading ammunition, as the subject of this invention, features an improved structure primarily due to the optimized design and enhanced sealing at the junction of the two main components — the metal base and the plastic case body. This ensures long-term sealing of the propellant charge stored inside the composite cartridge body and preserves the ballistic characteristics of the charge by protecting it from external influences during prolonged storage and use.

[0051] The technical solution of using plastic as a structural material for the cartridge body enables avoidance of significant contact stresses between the cartridge and the weapon’s chamber, facilitating easier extraction after firing. The use of standard construction materials — plastic and structural steels — for the stepped metal body, metal base, and threaded clamping ring allows manufacturing of such cartridges without heavy pressing equipment, galvanic treatment, machining, or painting processes, thereby achieving high technical and economic performance.

[0052] Currently, manufacturers aim to improve the design of artillery shells to reduce cost and enhance tactical, technical, and operational features. As a result, artillery composite plastic cartridges for both unitary and separate-loading ammunition must meet increased strength,functionality, and integrity requirements, ensure gas sealing of the propellant charge, reliable extraction, and compatibility with commonly available construction materials.

[0053] Sealing of the plastic cartridge for unitary and separate-loading ammunition is ensured by a sealing and hermetic plug that protects the charge from external influences under extreme battlefield conditions. Safety against static electricity during transport and operation is achieved by applying a graphite layer to the plastic cartridge body, completely preventing static charge accumulation that could potentially ignite the propellant.Description of the drawings

[0054] Sample embodiments of the plastic cartridge for unitary and separate-loading ammunition, subject of the utility model, are illustrated by the accompanying drawings, where:Fig- 1 - General view of a composite plastic cartridge for separate-loading with reduced variable charge.Fig. 2 - General view of a plastic cartridge for unitary loading, full charge, with central igniter and special profile for coupling with the projectile body.Fig. 3 - General view of a clamping threaded ring (specific example).Fig. 4 - General view of a metal base of the plastic cartridge.Fig. 5 - General view of a stepped metal cartridge case.Fig. 6 - General view of a cartridge body for separate-loading cartridges for full, variable, and reduced charge.Fig. 7 - General view of a composite plastic cartridge for separate-loading, reduced variable charge.Fig. 8 - General view of a plastic cartridge for separate-loading, full charge, with central igniter.Fig. 9 - General view of a plastic body for cartridges with separate-loading, for full and reduced variable charge.Fig. 10 - General view of a plastic cartridge for unitary loading with reduced charge, featuring a metal ring for connection with the projectile body.Example embodiment of the invention

[0055] A plastic cartridge case according to the invention, for separate cartridge and unitary loading, for a reduced variable charge, consists of a metal bottom 4, with a centrally formedstepped opening along the axis, in which a stepped-shaped metal body 1 is placed, in which a primer igniter 9 is mounted. A plastic housing 2 is attached to the stepped-shaped metal body 1, which is fixed immovably by means of a pressing threaded ring 3, thus ensuring a strong, non- detachable connection of the metal bottom 4 and the plastic housing 2 of the cartridge case.

[0056] In one variant of the plastic cartridge case for separate cartridge and unitary loading according to the invention, a tube 7 is fixedly fixed to the upper, front part of the igniter capsule 9, vertically oriented along the axis of the plastic housing 2, the height of the tube 7 being 2 / 3 of the height of the plastic housing 2. Radial openings 7a are made along the entire length of the tube 7, which are arranged in a circle, at equal distances from each other.

[0057] According to variant embodiments, the radial openings 7a can be made spirally along the length of the tube 7, or staggered relative to each other. An incendiary charge 8 is placed inside the tube 7, and it is preferable to use pyroxylin gunpowder. As already mentioned above, the plastic housing 2 is fixed to the stepped metal body 1 , which is fixedly mounted together with the metal bottom 4 by means of the pressing threaded ring 3.

[0058] According to a preferred embodiment, the tube 7 with radial holes 7a is fixedly attached to the metal stepped body 1 , for example by a threaded connection. The internal volume of the plastic housing 2 is filled with a propellant charge 10, and in the upper part of the plastic housing 2 are placed successively one above the other sealing 11 and sealing 12 plugs.

[0059] The maximum diameter D9 of the thread of the stepped metal body 1 is suitably selected for the purposes of mounting the plastic housing 2 and the pressing threaded ring 3, the purpose of which is to achieve a strong, guaranteed compact connection. It is appropriate that D9 is 1.35 mm from the minimum diameter d of the thread for winding the primer 9, in particular the primer cartridge case, and the diameter D of the hole for screwing the primer cartridge case is within 0.55 mm of the minimum diameter D of the protruding threaded part of the metal stepped-shaped body 1.

[0060] The maximum diameter dl for screwing the tube 7 with the radial holes 7a is 0.55 of the maximum diameter D9 of the stepped-shaped metal body 1.

[0061] According to a preferred embodiment, the plastic housing 2 of the cartridge case for unitary and separate cartridge case loading is made of plastic, the composition of which contains an antistatic substance, preferably in an amount of 3% of the total weight of the plastic housing 2.

[0062] According to another embodiment of the plastic cartridge case, for example when used for the manufacture of rifles ammunition, the antistatic substance is in an amount of 4.5% of the total weight of the plastic housing 2. The antistatic substance prevents the occurrence of an electric discharge of static electricity when the elements (bags with a discharge charge) rub against the walls of the plastic housing 2. The antistatic additive that is added to the material of the plastichousing 2 “migrates” to the surface of the housing, which is due to the relative incompatibility with the polymer, creating a conductive layer by absorbing atmospheric moisture.

[0063] When manufacturing the plastic housing 2 for separate cartridge case and unitary loading with an antistatic additive, it is appropriate that the process temperature does not exceed 250°C in order to avoid degradation or deterioration of the properties of the antistatic films, which can also be influenced by other ingredients in the film, for example other "migrating" additives, such as slip agents, leading to oily surfaces and changing the antistatic effect.

[0064] The antistatic additive can be used in the manufacture of the plastic housing 2 by various manufacturing methods, such as blasting, injection molding or casting, and its application results in an instant and long-lasting effect, long-term antistatic properties, efficiency at low humidity, but also a more pronounced low resistance obtained by using amine-based substances.

[0065] According to a preferred embodiment, the plastic housing 2 of the composite cartridge case for unitary and separate cartridge case loading can be made of high-density polyethylene, obtained by suspension and gas-phase methods, by polymerization of ethylene at low pressure.

[0066] In one variant embodiment of a plastic cartridge case for a shot with unitary loading, the diameter D5 of the pressing threaded ring 3 in accordance with its outer diameter to the diameter of the neck of the plastic housing, respectively DI and D3, the corresponding variant embodiment is equal to 0.85 of their largest diameter.

[0067] In one variant embodiment of a plastic cartridge for shots with unitary and separate cartridge loading, the thickness h2 of the metal bottom 4 is equal to no less than 0.77 mm of the thickness hl of the plastic housing 2, and the thickness of the pressing threaded ring 3 is equal to no less than 1.2 of the thickness of the metal bottom 4, with these parameters ensuring the necessary strength of the pressing threaded ring 3, respectively ensuring the strength and integrity of the connection of the plastic housing 2 with the metal bottom 4. Such strength is especially necessary in the conditions of vigorous extraction of the fired plastic cartridge at small angles of elevation of the barrel, when the energy of the recoil devices of the gun is significant, and as a consequence - the extraction speed of the fired plastic cartridge reaches its maximum value.

[0068] The pressing threaded ring 3 is provided with a central hole, with a thread diameter of said threaded ring DI, an outer diameter Fl and a thickness h, determined so that the pressing threaded ring 3 is screwed securely to the convex cylindrical surface with a diameter D9 of the stepped metal body 1.

[0069] It is suitable that the radius of connection of the forming outer cylindrical surface R3 of the pressing threaded ring 3 with its bottom surface is equal to 0.9 mm of the inner radius R1 of the metal bottom 4.

[0070] The embodiment of the outer fitting radius R of the forming side surface of the plastic housing 2 with its bottom surface is equal to 1.2 mm of the inner radius R1 of the stepped metal body 1.

[0071] It is suitable to pay attention to the circumstance that when implementing the fitting radius R of the outer forming surface of the plastic housing 2 with the metal bottom 4, i.e. with a radius smaller than 0.6 mm from the inner radius R1 of the stepped shaped metal body 1, in this embodiment the contact area of the mating surfaces of the plastic housing 2 and the metal bottom 4 with the sealing rubber pad is sharply reduced, as a result of which the required tightness of the connection between the metal bottom 4 and the plastic housing 2 cannot be ensured.

[0072] When the mating radius R of the outer forming surface of the plastic housing 2 with the metal bottom 4 is implemented, i.e. with a radius larger than 1.8 mm from the inner radius R1 of the metal bottom 4, the contact area of the mating surfaces between the plastic housing 2 and the metal bottom 4 and the rubber sealing pad is significantly increased. In this embodiment, uniform deformation of the metal bottom 4 with the rubber sealing pad is not ensured, as a result of which again, the guaranteed tightness of the connection between the metal bottom 4 and the plastic housing 2 cannot be achieved.

[0073] In one variant embodiment of a plastic cartridge case for unitary and separate cartridge case loading according to the utility model, a plastic cartridge case may contain a second pressing threaded ring 3, ensuring reliability of the connection of the plastic housing 2 with the metal bottom 4. This embodiment is suitable for cartridge cases used under operating conditions in guns with a high rate of fire and an automatic system for introducing the plastic cartridge case with the charge into the gun chamber.Operation of the invention

[0074] The proposed plastic cartridge case, intended for unitary and separate cartridge shots, works as follows:Variant 1.

[0075] The plastic housing 2 of the cartridge case (for separate and unitary loading for a reduced charge) is placed in the metal bottom 4, and the place for mounting the plastic housing 2 in the metal bottom 4 is previously smeared with a heat-resistant sealing paste, and the metal steppedshaped body 1 is placed in the stepped opening of the metal bottom 4. The outer surface of the stepped-shaped metal body 1 is smeared with a heat-resistant sealing paste, and in the inner spaceof the plastic housing 2 of the cartridge case, using a specialized key, the pressing threaded ring 3 is screwed into the thread of the stepped-shaped metal body 1, with a certain tightening force. Variant 2.

[0076] The plastic housing 2 of the cartridge case is placed in the metal bottom 4, and the place for mounting the plastic housing 2 in the metal bottom 4 is previously smeared with heat-resistant sealing paste, after which a stepped metal body 1 is placed in the stepped opening of the metal bottom 4, to which the metal tube 7 is mounted, in the inner space of which an ignition charge 8 is installed. The outer surface of the stepped metal body 1 is previously smeared with heat-resistant sealing paste, and in the inner space of the plastic housing 2 of the cartridge case, using a specialized key, the pressing threaded ring 3 with an outer diameter D5 is screwed into the thread of the stepped metal body 1, with a certain tightening force.

[0077] Inside the plastic cartridge case assembled in the described manner, the ejector charge 10, full or reduced for unitary and separate cartridge case shot, and its elements (flame arrester, copper suppressor) are filled, with the sealing 11 and sealing 12 plugs being placed in the upper part of the housing 2. In the opening of the mounted stepped shaped metal body 1 , the igniter capsule 9 is screwed with a specialized key, with a certain tightening force.

[0078] Before firing a shot with a shot for separate cartridge case loading, the shell body is placed in the gun chamber, placing it all the way in, i.e. until the copper guide belt engages in the rifling of the gun barrel, after which a plastic cartridge case with the ejector powder charge (full or reduced variable) is placed in the gun chamber and pressed all the way in. After closing the gun shutter and aiming, a shot is fired.

[0079] In the version with a reduced or variable charge, the igniter capsule 9 is activated, as a result of which ignition and complete combustion of the ejector charge 10 occurs. In the version with a full charge, the igniter capsule 9 is activated, igniting the ignition charge 8 located in the tube 7, which in turn simultaneously ignites the ejector charge 10, by means of the flowing fire pulse from the radial openings 7a of the tube 7 and performs complete combustion and formation of the necessary pressure from the exhaust gases.

[0080] The pressure from the gunpowder gases in the gun chamber, formed by the combustion of the ejector charge 10, acts on the walls of the plastic housing 2 and the walls of the metal bottom 4, causing radial deformations, and in parallel with this the projectile moves in the barrel of the gun and flies off with an initial speed in the direction of aiming. With this simultaneous deformation of the metal bottom 4 and the plastic body 2, favorable conditions are created for the interaction of the bottom 4 and the plastic body 2, ensuring the transverse strength of the plastic body 2.

[0081] Before firing a shot with a unitary cartridge case, the shot is placed in the gun chamber and moved to the stop, more precisely until the copper guide belt engages in the grooves of the gun barrel. After closing the gun shutter and aiming, a shot is fired.

[0082] In the reduced or variable charge variant, the igniter capsule 9 is activated, as a result of which ignition and complete combustion of the expelling charge 10 occurs.

[0083] In the full charge variant, the igniter capsule 9 is activated, which ignites the incendiary charge 8 located in the tube 7, which in turn simultaneously ignites the expelling charge 10, by means of the flowing fire pulse from the radial openings 7a of the tube 7 and carries out complete combustion and formation of the necessary pressure from the exhaust gases.

[0084] The pressure from the gunpowder gases in the gun chamber, formed by the combustion of the expelling charge 10 from pyroxene gunpowder, acts on the walls of the plastic housing 2 and the walls of the metal bottom 4, causing radial deformations. At the same time, the pressure from the gunpowder gases acts on the bottom of the projectile, causing the projectile to unclip from the case and move forward, and its flight from the barrel of the gun with an initial velocity in the direction of aiming. In this simultaneous deformation of the metal bottom 4 and the plastic body 2, favorable conditions are created for their interaction, ensuring the transverse strength of the plastic body 2.

[0085] In this case, the walls of the stepped metal body 1 with a diameter D are elastically deformed, while maintaining its strength and preventing the deformation of the means for ignition by gunpowder gases, and at the same time excluding the possibility of leakage, for example, breakthrough of gunpowder gases into the breech chamber of the gun. This ensures guaranteed extraction of the cartridge case after the shot, as well as the possibility of multiple use of the fired plastic cartridge cases for unitary and separate cartridge case loading.

[0086] The bottom part of the stepped shaped metal body 1 and the metal bottom 4 undergo radial and axial elastic-plastic deformations, without the formation of significant end wedgings between the outer surface of the metal bottom 4 and the gun chamber, which ensures the necessary reliability during extraction of the fired composite plastic cartridge for unitary and separate cartridge charging.The plastic housing 2 plastically deforms during firing, without the formation of cracks, due to the optimal degree of linear and radial deformation, as well as the high degree of the coefficient of relative elongation of the material from which the housing of the plastic cartridge 2 is made, which ensures the integrity of the structure.

[0087] The execution of the plastic cartridge for unitary and separate cartridge charging in accordance with the invention increases the reliability of its functioning in the composition of the artillery shot and, as a consequence, the effectiveness of the shooting as a whole.

[0088] The invention can be used in the development of various types of artillery shells.

Claims

Claims1. Plastic cartridge case for artillery shots, consisting of a metal bottom in the form of a disk, fixedly connected to a plastic body, with a stepped opening formed centrally in the metal bottom, in which a cylindrical, stepped-shaped metal body is mounted, in the inner space of which an igniter capsule is mounted by means of a threaded connection, and in the inner part of the plastic body is placed a pressing threaded ring, which is fixedly attached to a stepped-shaped metal body in which the igniter capsule is mounted, and between the metal bottom and the plastic body is placed a sealing rubber pad, whereby a propellant charge is placed in the inner volume of the plastic body, characterized in that the metal bottom (4) is filled with a recess in which the plastic body (2) is placed, wherein a threaded sector is formed in the convex part of the stepped-shaped metal body (1) with a maximum diameter D9 of the thread in which the pressing threaded ring (3) is installed, and the diameter of the stepped hole “d” is made with a size within the range of 0.42 mm to 0.68 mm of the minimum diameter D9 of the protruding threaded part of the stepped shaped metal body (1), in which a tube (7) is fixedly mounted in the front part of the stepped shaped metal body (1), oriented along the axis of the plastic housing (2), along the length of which radially oriented holes (7a) are made, and an ignition charge (8) is placed inside it and a metal ring (6) is located in the front cylindrical part of the plastic cartridge case.

2. Plastic cartridge case according to claim 1 , characterized in that the metal bottom is shaped as a metal disc with a diameter F, in which a stepped opening with diameters Dl l and DI 2 is centrally formed, and the recess has a diameter D7, a depth h4 and a radius of curvature Rl.

3. Plastic cartridge case according to claim 1, characterized in that the thickness of the metal disc “h2” is equal to 0.6 to 0.8 mm of the thickness of the bottom of the plastic housing “hl”.

4. Plastic cartridge case according to claim 1, characterized in that the plastic housing (2) is made as a single element.

5. Plastic cartridge case according to claim 1, characterized in that the plastic body (2) is made of plastic, the composition of which contains an antistatic substance, in an amount of 3 to 5% of the total weight of the plastic body (2) and a UV additive, in an amount of not less than 2.5% relative to the total weight of the plastic body (2), the antistatic substance being graphite.

6. Plastic cartridge case according to claim 1, characterized in that a protective zinc-phosphate or chromium coating is applied to the metal surface of the stepped shaped metal body (1), the metal bottom (4) and the metal ring (6), with a thickness of not less than 7 pm.

7. Plastic cartridge case according to claim 1, characterized in that black smoke powder is placed as an incendiary charge (8), located in the inner space of the tube (7).

8. Plastic cartridge case according to claim 1, characterized in that pyroxylin gunpowder is used for the propellant charge (10).

9. Plastic cartridge case according to claim 1, characterized in that the length of the tube (7) with radial holes (7a) is at least 2 / 3 of the height of the plastic housing (2) and is located along its axis.

10. Plastic cartridge case according to claim 1, characterized in that the radial holes (7a) are made along the entire length of the tube (7), being arranged in the form of concentrically arranged circles, in a spiral or staggered pattern.

11. Plastic cartridge case according to claim 1 , characterized in that the metal ring (6) located in the front part of the plastic housing (2) has a wall thickness of 1.2 - 2 mm.

12. Plastic cartridge case according to claim 1, characterized in that in the front inner part of the plastic housing (2) an inner spherical rim with a radius of curvature R3 and a diameter smaller than the diameter of a channel formed in the bottom of the projectile and intended for fixing and connecting the plastic housing (2) with the bottom of the projectile is structurally formed.

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