Barrel as well as method for the manufacturing of barrel segments and method for the manufacturing of a barrel and a firing device comprising a barrel

Abstract

The present invention relates to a method for producing barrel segments by arranging a capsule assembly around a template core. Powder is then arranged in the cavity that surrounds the template core. The powder is pressed to join the powder with the capsule assembly and then the template core is removed.The invention further relates to a method for the manufacturing of a barrel, barrel and a barrel with a firing device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a National Stage entry of PCT Application No. PCT / SE2024 / 050066, entitled “BARREL AS WELL AS METHOD FOR THE MANUFACTURING OF BARREL SEGMENTS AND METHOD FOR THE MANUFACTURING OF A BARREL AND A FIRING DEVICE COMPRISING A BARREL”, filed Jan. 25, 2024, which claims priority to SE Application No. 2300011-0, entitled “BARREL AS WELL AS METHOD FOR THE MANUFACTURING OF BARREL SEGMENTS AND METHOD FOR THE MANUFACTURING OF A BARREL AND A FIRING DEVICE COMPRISING A BARREL”, filed Feb. 9, 2023, the disclosures of which are incorporated by reference herein in their entireties.TECHNICAL FIELD

[0002] The present invention relates to a method for the production of barrel segments comprising arranging a capsule structure so that it surrounds a template core, and where powder is arranged in the cavity between the capsule structure and the template core and where the powder is pressed so that powder and capsule assembly are joined together and where the template core is removed for the production of a barrel segment. The invention further relates to a method for the manufacturing of a barrel, barrel and a firing device.BACKGROUND

[0003] Barrel-based weapons are fired off by means of combusting gunpowder, thus bringing about the expansion of gas, where said expansion of gas moves a projectile within a barrel. Barrels designed with rifling preferably designed with a rifling having a pitch over the extent of the barrel, which means that the projectile is rotated during the firing process. Rotation of the projectile is desirable to provide a rotation stabilized projectile, i.e. the projectile rotates, after the projectile has left the barrel. As an alternative to a rotation-stabilized projectile, the projectile can be stabilized by means of, for example, fins. In such cases, it may be preferrable for the projectile not to rotate when it leaves the barrel. Thus, in such cases, the projectile can be outfitted with a sliding belt, which causes the projectile to either not rotate or only partially rotate during the projectile's launch phase when the projectile is fired in a rifled barrel. When the projectile leaves the barrel in this case, the projectile is stabilized by fins arranged on the projectile. As an alternative, the projectile can be fired from a barrel without rifling, also called smooth bore, which results in no rotational force being transmitted to the projectile during the firing process.

[0004] Conventionally, barrels are manufactured by means of machining entailing cutting a forged material. These manufacturing methods are both costly and time-consuming and result in a barrel that is designed based on production limitations and not based on the functional requirements of the barrel.

[0005] Conventional rifling of barrels includes several stages of cutting processing including drilling, turning, honing and rifling with equipment specially adapted for the purpose, which in part entails high costs but also limited opportunities to change the design of the rifling.

[0006] Examples of the manufacturing method for rifled barrels are given in patent document EP 0 339 692 A2, which describes a method for manufacturing a barrel where an inner template is manufactured, upon which layers of refractory materials in powder form are arranged.

[0007] The above prior art does not show powder being arranged between the inner template and a capsule structure during manufacture.

[0008] Additional problems which the present invention seeks to solve will become apparent in connection with the following detailed description of the various embodiments.SUMMARY OF THE INVENTION

[0009] The purpose of the present invention is to achieve an improved way of manufacturing an improved barrel with the possibility of adapting the length and the design of the rifling based on the technical requirements for the barrel and not on the basis of technical limitations on manufacture.

[0010] The invention relates to a method for producing barrel segments, where the method includes the following steps:

[0011] i.) a capsule assembly is arranged so that it surrounds a template core, where the template core is fully or partially arranged with rifling for embossing rifling patterns on the barrel segment,

[0012] ii.) powder is arranged in the cavity between the capsule assembly and the template core,

[0013] iii.) the powder is pressed so that the powder and the capsule assembly are joined together,

[0014] iv.) the template core is removed for the manufacture of a barrel segment.

[0015] According to further aspects for the method of manufacturing a barrel segment according to the invention, the following applies:

[0016] that the powder is pressed using high pressure and heat, also called Hot Isostatic Pressing, HIP.

[0017] that the barrel is heat-treated and hardened using Hot Isostatic Pressing during the finishing of a barrel segment.

[0018] that a metal film is arranged on the template core.

[0019] that the metal film is manufactured out of tantalum.

[0020] that the powder completely or partially consists of tantalum.

[0021] that a tantalum pipe is arranged on the template core.

[0022] The invention is further comprised by a method for manufacturing a barrel, characterized in that the method includes the following steps:

[0023] i.) heating up a barrel casing,

[0024] ii.) arranging a first barrel segment, including chambers, in the heated barrel casing,

[0025] iii.) cooling a barrel consisting of a barrel casing arranged with barrel segments.

[0026] According to further aspects for the method of manufacturing a barrel according to the invention, the following applies:

[0027] that at least a second barrel segment is arranged after the first barrel segment in the barrel casing prior to the barrel consisting of a barrel casing outfitted with barrel segments being cooled off.

[0028] The invention also comprises a barrel.

[0029] The invention also comprises a firing device including a firing barrel including a barrel.

[0030] By manufacturing barrels or barrel components with a HIP, an improved barrel can be manufactured where the length of the barrel can be adapted based on the needs that exist instead of based on manufacturing technical limitations that currently limit barrel length. Furthermore, the rifling of the barrel can be carried out in a simpler way and with greater freedom to choose the design of the rifling compared to today's manufacturing methods for the rifling of barrels.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be described below by reference to the figures that are included there:

[0032] FIG. 1 shows a schematic of the manufacture of a barrel segment according to one embodiment of the invention.

[0033] FIG. 2a shows a capsule assembly according to one embodiment of the invention.

[0034] FIG. 2b shows a cross-section of a capsule assembly according to one embodiment of the invention.

[0035] FIG. 3 shows a barrel according to one embodiment of the invention.

[0036] FIG. 4 shows the template core according one embodiment of the invention.

[0037] FIG. 5 shows the process steps for Hot Isostatic Pressing, HIP, when manufacturing a barrel segment according to one embodiment of the invention.

[0038] FIG. 6 shows the process steps for the manufacturing of a barrel from barrel segments, according to an embodiment of the invention.DETAILED DESCRIPTION OF THE DRAWINGS

[0039] The present invention shows embodiments of manufacturing methods for barrels and / or barrel components, such as barrel segments.

[0040] An ejection device, also termed a cannon, a howitzer, or a piece, in the sense of an artillery piece, has the goal of making use of a propellant for the purpose of firing a projectile. Preferably, a propellant, such as gunpowder, is initiated in one part of the cannon, oftentimes a chamber specifically adapted to the purpose. Initiation takes place by way of igniting the propellant, for instance by means of an ignition cartridge or an igniter in a munitions device, which is initiated by means of striking. Other methods for igniting the propellant may include ignition of the propellant by means of laser energy or electric energy. The propellant burns at a high rate and results in large amounts of gas being produced, which creates a gas pressure in the chamber which propels the projectile out of the barrel of the firing device. The propellant has been adapted in order to generate a constant pressure on the projectile during the entire barrel procedure, to the greatest extent possible, as the projectile moves in the barrel, which results in the projectile leaving the mouth of the barrel with high speed.

[0041] Projectiles, such as various types of grenades, generally include some form of warhead and some form of barrel which initiates the warhead. Fuzes can be of different types where contact fuzes are common for projectiles that are meant to burst when in contact with an object, timed fuzes when the projectile is meant to burst at a certain predetermined time and proximity fuzes when the projectile is meant to burst when an object comes within a certain distance from the projectile. The use of proximity fuzes is preferred when confronting flying vessels and usually for medium caliber ammunition, such as 40 mm and 57 mm, while timed fuzes and contact fuzes can be used when confronting a large number of various different objects. It is advantageous to combine various types of fuze functions in one and the same fuze, for instance in order for the projectile to burst after a certain time if it fails to detect any object, and so on.

[0042] It is advantageous for the warhead to comprise some type of explosive substance, as well as some type of shattering casing which encloses the explosive substance. Various types of propellants, such as fins, can furthermore be arranged in either the barrel or in its own subcomponent.

[0043] In order to stabilize the projectiles once the projectiles have left the barrel, the projectiles are preferably designed with rotation or with fins. In cases where the projectiles are designed with rotation, the projectiles are said to be rotationally stabilized and in cases where the projectiles are arranged with fins, the projectiles are said to be fin-stabilized. Fin-stabilized projectiles should have no rotation, or low rotation, when leaving the barrel.

[0044] To achieve rotation on the projectiles, the barrel is often designed with rifling, to which the projectile connects during the firing process. Rifling means that the barrel in a firearm, the barrel, is provided with spiral-shaped rifling. The opposite is a smooth-bore barrel. When the rifling engages the projectile during firing, the projectile is made to rotate along its longitudinal axis. Due to the rotation, minor irregularities or damage to the projectile will not cause a drift in the trajectory of the projectile. Rotation is also necessary for an elongated (torpedo-shaped) projectile to maintain its direction after leaving the barrel and not start tumbling around. This is referred to as the projectile being rotation-stabilized. In smooth-bore weapons, only round (spherical) projectiles or fin-stabilized projectiles can be fired. An elongated projectile without fins will tumble as it leaves the muzzle.

[0045] Thus, rifling consists of grooves that are integrated into the track of the barrel, and the elevation in between is referred to as barriers. The rifling of fine-caliber firearms usually consists of four grooves that are turned to the right, while cannons, such as artillery pieces, have more grooves depending on the caliber of the launching device. In order for the rifling to be able to engage the projectile, the projectile must either be slightly larger than the diameter between the barriers, which is common for fine-caliber weapons, or be equipped with a special flange, called a belt, which has a slightly larger diameter than the barriers, which is common in projectiles with a diameter greater than 20 mm. The belt can be made out of plastic, composite material or a soft metal, such as copper or copper alloy. The length of the barrel on which the groove rotates an entire revolution is called the pitch and is usually the number of inches per revolution.

[0046] Most barrels include rifling, and, by arranging projectiles with sliding belts, both rotation-stabilized and fin-stabilized projectiles can be launched with rifled barrels. Smooth-bore barrels are basically only used for weapon systems intended to armored combat vehicles, as the rotation of the projectile means that the directed explosive action, RSV, is less effective since the centrifugal force causes the beam to be spread out.

[0047] In the embodiment comprising that barrels or components for barrels are manufactured with HIP, materials with high resistance to abrasion and thermal erosion gases, which arise when projectiles are fired from a barrel, may be used. Since materials with high resistance to abrasion and thermal erosion gases often have higher costs relative to other materials that are suitably used in HIP, these materials can be used optimally in HIP Cladding to create a component with high performance but with as low a manufacturing cost as possible. Advantages of HIP Cladding are that the physical limitations regarding the thickness of added material, such as the surface treatment that is added, are not limited compared to other surface treatment methods. This means that a thicker layer of the added material can be created. With HIP Cladding, it is also possible to combine metals with composites. With HIP Cladding, a bimetallic component can be manufactured without welding or fastening techniques, resulting in a high-strength component. Components manufactured with HIP Cladding have an improved lifetime and performance compared to components manufactured with the substrate alloy. Manufacturing barrel components / segments and fuzes with HIP Cladding involves limited machining and / or surface treatment operations as well as a reduced number of process steps and thus shortens lead time compared to forged and coated components. HIP Cladding allows selected surfaces to be bonded to the surface by diffusion; coating of a suitable resistant material in powder form or solid form to a solid substrate to provide a surface with increased resistance to wear and / or corrosion via the production technique encapsulation (HIP Cladding) and HIP.

[0048] Hot isostatic pressing, HIP (Hot Isostatic Pressing), is a production process to control the grain size and structure of the material. HIP also allows metal powder, polymer powder, ceramic powder and composite powder to be pressed into a solid form. The advantages include the fact that all the empty spaces inside metal components that are created through additional manufacturing methods are removed and that mechanical properties such as fatigue resistance / fatigue strength, toughness, plasticity and impact resistance are improved. Furthermore, HIP can create a dense material from metal powder, composite powder, polymer powder or ceramic powder without melting, and materials with partially different characteristics can be combined in the same component.

[0049] Using HIP, a solid material can be created from powder with superior properties because the powder / powder components have a fine, uniform grain size and an isotropic structure. Furthermore, with HIP, different metals can be joined together without needing a temperature-limiting adhesive. Using HIP, several diffusion bonds can be achieved in one process cycle. HIP works for a large number of metal alloys, such as polymers and ceramic material. For example, alloys with nickel, cobalt, tungsten, titanium, molybdenum, aluminum, copper and iron, oxide-and nitride ceramics, glass, intermetallic substances and polymers. HIP enables the bonding and combining of materials that otherwise cannot be combined, i.e. composites.

[0050] FIG. 1 shows a schematic sketch of the manufacture of a barrel segment 1 where a template core 20 is arranged in an outer tube 11, which is part of a capsule construction, so that a void, a cavity 30, is arranged between the capsule construction and the template core 20. In the cavity 30, powder can be arranged to manufacture a barrel segment 1 with HIP. barrel segment 1 can be made up of a complete barrel, but can also be made up of components for a complete barrel, then called a barrel segment. A complete barrel can thus be arranged by arranging several components, also called barrel segments, to complete a complete barrel.

[0051] FIG. 2a shows a view of a HIP container in the form of a capsule construction 10 for manufacturing a component for a barrel. The HIP container 10 is arranged with connection device 12, 14, for evacuating air, vacuum pumping, before and / or during the implementation of the manufacturing method, as well as a front bottom plate 16 and an outer tube 11.

[0052] FIG. 2b shows a cross-sectional view of a HIP container in the form of a capsule construction 10 for manufacturing a component for a barrel. The HIP container 10 is arranged with connection device 12, 14, for evacuation of air, vacuum pumping, before and / or during the implementation of the manufacturing method and a front bottom plate 16 and a rear bottom plate 18 and an outer tube 11. The powder is arranged freely in the HIP container in the form of the capsule assembly 10. between the capsule assembly 10 and a template core 20. Through continued HIP treatment, the powder can be fixed in the intended position in order to create a barrel segment 1. The material can be applied in powder form and shaken when they are located inside a HIP container in the form of capsule assembly 10, which is a surrounding component designed to hold powder, where powder, as the material to be applied, is arranged freely in the capsule assembly 10. Through continued HIP treatment, the powder can be fixed in the intended position in order to create a barrel segment 1. Manufacturing methods involving powder have advantages under cramped manufacturing conditions because the material supplied can reach into areas with small dimensions. Capsule assembly 10 is designed with a connecting device for evacuating air and vacuum pumping before and / or during the manufacturing process. Preferably, a first type of powder is provided in the capsule assembly 10 for the barrel other than the intermediate template core 20 and second type of powder is placed against the template core 20, which is not shown in the figure. The capsule assembly 10 is preferably made out of any material that a person skilled in the art considers suitable for the purpose. In one embodiment, the material in capsule assembly 10 is black sheet plate, and in another embodiment, the material is stainless steel, which also provides a rust-protection function for the barrel segment 1. The subcomponents of the capsule assembly can be manufactured additionally.

[0053] FIG. 3 shows a barrel 60 made of a number of barrel segments 1, 1′ arranged in a barrel casing 62. A complete barrel 60 includes additional barrel segments so that the entire barrel casing 62 is arranged with barrel segments. The first barrel segment 1 is arranged with chamber 2 and positioned where the barrel is arranged against the launch device and where the projectile is arranged for launch in the barrel 60. After the first barrel segment 1, subsequent barrel segments 1′, 1″ are arranged until the mouth of the barrel 4. Respective barrel segments 1, 1′, 1″ are manufactured based on the manufacturing method stated above and are arranged in a barrel casing 62 by heating the barrel casing 62 and thereby expanding to a state such that the barrel segments 1, 1′, 1″ can be arranged in the barrel casing 62. After the barrel segments 1, 1′, 1″ are arranged in the barrel casing 62, the barrel casing can cool so that the barrel casing contracts and barrel segments 1, 1′, 1″ are retained in the barrel casing 62 so that a complete barrel 60 is created. When a certain compressive stress is applied to the barrel segments 1, 1′, 1″ of the cooled barrel casing 62, autofrettage is achieved on the inner surface of the barrel, which results in improved resistance to crack propagation and / or crack formation.

[0054] FIG. 4 shows a template core 20 for manufacturing the first barrel segment 1. Template core 20 is arranged with a first part 21, for manufacturing chambers in barrel segment 1, and a second part 22 for manufacturing fluting in barrel segment 1. The template core is preferably made of metal but can also be made of other materials suitable for the continued method of manufacturing barrel segments.

[0055] FIG. 5 shows the manufacturing method 100 for barrel segment 1 with HIP. The outer tube 11, the rear bottom plate 18 and the front bottom plate 16 are arranged jointly in order to create a capsule assembly 10 in the step Designing a capsule assembly 102. A template core 20 is also arranged in the capsule assembly 10. A capsule assembly 10, also called a HIP container, is a device in which powder is arranged in a manner that allows it to be shaped into a HIPed body under high temperature and high pressure.

[0056] Powder in the capsule assembly 10 is arranged in the step Powder is arranged in the capsule assembly 104 by arranging powder between the template core 20 and outer tube 11. The template core 20 can be centered in the outer tube 11 by affixing the template core 20 to the rear bottom plate 18 and the front bottom plate 16.

[0057] After the powder material has been placed in the capsule assembly 10, the capsule assembly 10 is evacuated, vibrated and sealed in order to evenly distribute the powder in the capsule assembly 10 during the Evacuation, Vibration and Sealing step for capsule assembly 106. HIP is then carried out in the HIP 108 stage, i.e. a gas is used to create isostatic pressure on the capsule assembly 10 via a connecting device on the capsule assembly 60 that supplies the gas. Before the gas is supplied to the capsule assembly, the capsule assembly is vacuum-pumped or otherwise evacuated of air or the filling gas / fluid placed in the capsule assembly 10 prior to evacuation, e.g. by rinsing the assembly with a noble gas. Subsequently, the entire capsule assembly 10 is simultaneously heated to create a preform or a HIPed body. The HIP temperature is preferably 20% below the melting temperature for the material; for martensitic steel, the HIP temperature during the phase conversion (which is in the order of magnitude of 80% of the material's melting point). After the hot isostatic pressing is completed, the body can undergo heat treatment / hardening 110, which means that the now merged body is heated. After heat treatment, the material is suitable for processing, for example by means of machining entailing cutting, so that excess material, for example material covering the opening for the exit passage for gas flow and possibly parts of the HIP container is processed away in the step Machining / pickling 112 where machining entailing cutting such as lathe turning or milling but also pickling or other chemical treatment such as treatment with acid can be performed. The template core 20 is preferably removed by a combination of mechanical machining, such as lathe turning / drilling and pickling so that the riffling embedded in the barrel emerges. Where applicable, a surface treatment 114 is also performed.

[0058] Once barrel segment 1 is finalized, multiple barrel segments 1 may be assembled in order to create a barrel.

[0059] The material used for the powder is preferably factory steel or martensitic stainless steel with high concentrations of chromium and nickel, potentially with refractory material forming a layer on the muzzle brake in order to better withstand erosion from gun powder gases.

[0060] FIG. 6 shows manufacturing method 200 for manufacturing a barrel 60 from multiple barrel segments 1, 1′, 1″. Initially, barrel sheath 62, in which the barrel segments are arranged, is heated in the step Heating of barrel sheath 202. Once the barrel sheath 62 is heated, the barrel sheath 62 expands, which means that barrel segments 1, 1′, 1″ can be arranged in the barrel sheath 62. In the step barrel segments are arranged in barrel casing 204, one or more barrel segments 1, 1′, 1″ are arranged in barrel casing 62. In the step barrel segments including chambers are arranged in barrel casing 206, barrel segments with chamber 1 are arranged in the barrel casing to create a complete barrel 60. After the arrangement of barrel segments, the barrel can be cooled, which takes place in the step Cooling of barrel casing 208. When the barrel casing with barrel segments is cooled, a complete barrel 60 is completed, which can then be arranged in a firing device.

[0061] In an alternative embodiment regarding manufacturing method 200′ for barrel 60, only one barrel segment 1 is used Initially, the barrel sheath 62, in which the barrel segment 1 is arranged, is heated in the step Heating of barrel sheath 202. When the barrel casing 62 is heated, the barrel casing 62 expands, which means that the barrel segment 1 can be arranged in the barrel casing 62. In the step barrel segment is arranged in barrel casing 204, no barrel segment is arranged in the barrel casing 62 for the alternative embodiment of manufacturing method 200′ for barrels, instead arranged, in the step barrel segment comprising chambers are arranged in barrel casing 206, a barrel segment with chamber 1 in the barrel casing for the creation of a complete barrel 60. After the arrangement of barrel segments, the barrel can be cooled, which takes place in the step Cooling of barrel casing 208. When the barrel casing with barrel segments is cooled, a complete barrel 60 is completed, which can then be arranged in a firing device.

[0062] The invention is not limited to the embodiments specifically shown, but can be varied in different ways within the framework of the claims.

[0063] For instance, it is clear that the choice of material, choice of geometric forms, the elements and details included in the barrel or barrel components are adapted to the weapons system(s), platforms and other construction-related properties that are applicable at this time.

[0064] Furthermore, all types of barrels and barrel components, such as small caliber, medium caliber and large caliber barrels are included.

Examples

Embodiment Construction

[0039]The present invention shows embodiments of manufacturing methods for barrels and / or barrel components, such as barrel segments.

[0040]An ejection device, also termed a cannon, a howitzer, or a piece, in the sense of an artillery piece, has the goal of making use of a propellant for the purpose of firing a projectile. Preferably, a propellant, such as gunpowder, is initiated in one part of the cannon, oftentimes a chamber specifically adapted to the purpose. Initiation takes place by way of igniting the propellant, for instance by means of an ignition cartridge or an igniter in a munitions device, which is initiated by means of striking. Other methods for igniting the propellant may include ignition of the propellant by means of laser energy or electric energy. The propellant burns at a high rate and results in large amounts of gas being produced, which creates a gas pressure in the chamber which propels the projectile out of the barrel of the firing device. The propellant has b...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a National Stage entry of PCT Application No. PCT / SE2024 / 050066, entitled “BARREL AS WELL AS METHOD FOR THE MANUFACTURING OF BARREL SEGMENTS AND METHOD FOR THE MANUFACTURING OF A BARREL AND A FIRING DEVICE COMPRISING A BARREL”, filed Jan. 25, 2024, which claims priority to SE Application No. 2300011-0, entitled “BARREL AS WELL AS METHOD FOR THE MANUFACTURING OF BARREL SEGMENTS AND METHOD FOR THE MANUFACTURING OF A BARREL AND A FIRING DEVICE COMPRISING A BARREL”, filed Feb. 9, 2023, the disclosures of which are incorporated by reference herein in their entireties.TECHNICAL FIELD

[0002] The present invention relates to a method for the production of barrel segments comprising arranging a capsule structure so that it surrounds a template core, and where powder is arranged in the cavity between the capsule structure and the template core and where the powder is pressed so that powder and capsule assembly are joined together and where the template core is removed for the production of a barrel segment. The invention further relates to a method for the manufacturing of a barrel, barrel and a firing device.BACKGROUND

[0003] Barrel-based weapons are fired off by means of combusting gunpowder, thus bringing about the expansion of gas, where said expansion of gas moves a projectile within a barrel. Barrels designed with rifling preferably designed with a rifling having a pitch over the extent of the barrel, which means that the projectile is rotated during the firing process. Rotation of the projectile is desirable to provide a rotation stabilized projectile, i.e. the projectile rotates, after the projectile has left the barrel. As an alternative to a rotation-stabilized projectile, the projectile can be stabilized by means of, for example, fins. In such cases, it may be preferrable for the projectile not to rotate when it leaves the barrel. Thus, in such cases, the projectile can be outfitted with a sliding belt, which causes the projectile to either not rotate or only partially rotate during the projectile's launch phase when the projectile is fired in a rifled barrel. When the projectile leaves the barrel in this case, the projectile is stabilized by fins arranged on the projectile. As an alternative, the projectile can be fired from a barrel without rifling, also called smooth bore, which results in no rotational force being transmitted to the projectile during the firing process.

[0004] Conventionally, barrels are manufactured by means of machining entailing cutting a forged material. These manufacturing methods are both costly and time-consuming and result in a barrel that is designed based on production limitations and not based on the functional requirements of the barrel.

[0005] Conventional rifling of barrels includes several stages of cutting processing including drilling, turning, honing and rifling with equipment specially adapted for the purpose, which in part entails high costs but also limited opportunities to change the design of the rifling.

[0006] Examples of the manufacturing method for rifled barrels are given in patent document EP 0 339 692 A2, which describes a method for manufacturing a barrel where an inner template is manufactured, upon which layers of refractory materials in powder form are arranged.

[0007] The above prior art does not show powder being arranged between the inner template and a capsule structure during manufacture.

[0008] Additional problems which the present invention seeks to solve will become apparent in connection with the following detailed description of the various embodiments.SUMMARY OF THE INVENTION

[0009] The purpose of the present invention is to achieve an improved way of manufacturing an improved barrel with the possibility of adapting the length and the design of the rifling based on the technical requirements for the barrel and not on the basis of technical limitations on manufacture.

[0010] The invention relates to a method for producing barrel segments, where the method includes the following steps:

[0011] i.) a capsule assembly is arranged so that it surrounds a template core, where the template core is fully or partially arranged with rifling for embossing rifling patterns on the barrel segment,

[0012] ii.) powder is arranged in the cavity between the capsule assembly and the template core,

[0013] iii.) the powder is pressed so that the powder and the capsule assembly are joined together,

[0014] iv.) the template core is removed for the manufacture of a barrel segment.

[0015] According to further aspects for the method of manufacturing a barrel segment according to the invention, the following applies:

[0016] that the powder is pressed using high pressure and heat, also called Hot Isostatic Pressing, HIP.

[0017] that the barrel is heat-treated and hardened using Hot Isostatic Pressing during the finishing of a barrel segment.

[0018] that a metal film is arranged on the template core.

[0019] that the metal film is manufactured out of tantalum.

[0020] that the powder completely or partially consists of tantalum.

[0021] that a tantalum pipe is arranged on the template core.

[0022] The invention is further comprised by a method for manufacturing a barrel, characterized in that the method includes the following steps:

[0023] i.) heating up a barrel casing,

[0024] ii.) arranging a first barrel segment, including chambers, in the heated barrel casing,

[0025] iii.) cooling a barrel consisting of a barrel casing arranged with barrel segments.

[0026] According to further aspects for the method of manufacturing a barrel according to the invention, the following applies:

[0027] that at least a second barrel segment is arranged after the first barrel segment in the barrel casing prior to the barrel consisting of a barrel casing outfitted with barrel segments being cooled off.

[0028] The invention also comprises a barrel.

[0029] The invention also comprises a firing device including a firing barrel including a barrel.

[0030] By manufacturing barrels or barrel components with a HIP, an improved barrel can be manufactured where the length of the barrel can be adapted based on the needs that exist instead of based on manufacturing technical limitations that currently limit barrel length. Furthermore, the rifling of the barrel can be carried out in a simpler way and with greater freedom to choose the design of the rifling compared to today's manufacturing methods for the rifling of barrels.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be described below by reference to the figures that are included there:

[0032] FIG. 1 shows a schematic of the manufacture of a barrel segment according to one embodiment of the invention.

[0033] FIG. 2a shows a capsule assembly according to one embodiment of the invention.

[0034] FIG. 2b shows a cross-section of a capsule assembly according to one embodiment of the invention.

[0035] FIG. 3 shows a barrel according to one embodiment of the invention.

[0036] FIG. 4 shows the template core according one embodiment of the invention.

[0037] FIG. 5 shows the process steps for Hot Isostatic Pressing, HIP, when manufacturing a barrel segment according to one embodiment of the invention.

[0038] FIG. 6 shows the process steps for the manufacturing of a barrel from barrel segments, according to an embodiment of the invention.DETAILED DESCRIPTION OF THE DRAWINGS

[0039] The present invention shows embodiments of manufacturing methods for barrels and / or barrel components, such as barrel segments.

[0040] An ejection device, also termed a cannon, a howitzer, or a piece, in the sense of an artillery piece, has the goal of making use of a propellant for the purpose of firing a projectile. Preferably, a propellant, such as gunpowder, is initiated in one part of the cannon, oftentimes a chamber specifically adapted to the purpose. Initiation takes place by way of igniting the propellant, for instance by means of an ignition cartridge or an igniter in a munitions device, which is initiated by means of striking. Other methods for igniting the propellant may include ignition of the propellant by means of laser energy or electric energy. The propellant burns at a high rate and results in large amounts of gas being produced, which creates a gas pressure in the chamber which propels the projectile out of the barrel of the firing device. The propellant has been adapted in order to generate a constant pressure on the projectile during the entire barrel procedure, to the greatest extent possible, as the projectile moves in the barrel, which results in the projectile leaving the mouth of the barrel with high speed.

[0041] Projectiles, such as various types of grenades, generally include some form of warhead and some form of barrel which initiates the warhead. Fuzes can be of different types where contact fuzes are common for projectiles that are meant to burst when in contact with an object, timed fuzes when the projectile is meant to burst at a certain predetermined time and proximity fuzes when the projectile is meant to burst when an object comes within a certain distance from the projectile. The use of proximity fuzes is preferred when confronting flying vessels and usually for medium caliber ammunition, such as 40 mm and 57 mm, while timed fuzes and contact fuzes can be used when confronting a large number of various different objects. It is advantageous to combine various types of fuze functions in one and the same fuze, for instance in order for the projectile to burst after a certain time if it fails to detect any object, and so on.

[0042] It is advantageous for the warhead to comprise some type of explosive substance, as well as some type of shattering casing which encloses the explosive substance. Various types of propellants, such as fins, can furthermore be arranged in either the barrel or in its own subcomponent.

[0043] In order to stabilize the projectiles once the projectiles have left the barrel, the projectiles are preferably designed with rotation or with fins. In cases where the projectiles are designed with rotation, the projectiles are said to be rotationally stabilized and in cases where the projectiles are arranged with fins, the projectiles are said to be fin-stabilized. Fin-stabilized projectiles should have no rotation, or low rotation, when leaving the barrel.

[0044] To achieve rotation on the projectiles, the barrel is often designed with rifling, to which the projectile connects during the firing process. Rifling means that the barrel in a firearm, the barrel, is provided with spiral-shaped rifling. The opposite is a smooth-bore barrel. When the rifling engages the projectile during firing, the projectile is made to rotate along its longitudinal axis. Due to the rotation, minor irregularities or damage to the projectile will not cause a drift in the trajectory of the projectile. Rotation is also necessary for an elongated (torpedo-shaped) projectile to maintain its direction after leaving the barrel and not start tumbling around. This is referred to as the projectile being rotation-stabilized. In smooth-bore weapons, only round (spherical) projectiles or fin-stabilized projectiles can be fired. An elongated projectile without fins will tumble as it leaves the muzzle.

[0045] Thus, rifling consists of grooves that are integrated into the track of the barrel, and the elevation in between is referred to as barriers. The rifling of fine-caliber firearms usually consists of four grooves that are turned to the right, while cannons, such as artillery pieces, have more grooves depending on the caliber of the launching device. In order for the rifling to be able to engage the projectile, the projectile must either be slightly larger than the diameter between the barriers, which is common for fine-caliber weapons, or be equipped with a special flange, called a belt, which has a slightly larger diameter than the barriers, which is common in projectiles with a diameter greater than 20 mm. The belt can be made out of plastic, composite material or a soft metal, such as copper or copper alloy. The length of the barrel on which the groove rotates an entire revolution is called the pitch and is usually the number of inches per revolution.

[0046] Most barrels include rifling, and, by arranging projectiles with sliding belts, both rotation-stabilized and fin-stabilized projectiles can be launched with rifled barrels. Smooth-bore barrels are basically only used for weapon systems intended to armored combat vehicles, as the rotation of the projectile means that the directed explosive action, RSV, is less effective since the centrifugal force causes the beam to be spread out.

[0047] In the embodiment comprising that barrels or components for barrels are manufactured with HIP, materials with high resistance to abrasion and thermal erosion gases, which arise when projectiles are fired from a barrel, may be used. Since materials with high resistance to abrasion and thermal erosion gases often have higher costs relative to other materials that are suitably used in HIP, these materials can be used optimally in HIP Cladding to create a component with high performance but with as low a manufacturing cost as possible. Advantages of HIP Cladding are that the physical limitations regarding the thickness of added material, such as the surface treatment that is added, are not limited compared to other surface treatment methods. This means that a thicker layer of the added material can be created. With HIP Cladding, it is also possible to combine metals with composites. With HIP Cladding, a bimetallic component can be manufactured without welding or fastening techniques, resulting in a high-strength component. Components manufactured with HIP Cladding have an improved lifetime and performance compared to components manufactured with the substrate alloy. Manufacturing barrel components / segments and fuzes with HIP Cladding involves limited machining and / or surface treatment operations as well as a reduced number of process steps and thus shortens lead time compared to forged and coated components. HIP Cladding allows selected surfaces to be bonded to the surface by diffusion; coating of a suitable resistant material in powder form or solid form to a solid substrate to provide a surface with increased resistance to wear and / or corrosion via the production technique encapsulation (HIP Cladding) and HIP.

[0048] Hot isostatic pressing, HIP (Hot Isostatic Pressing), is a production process to control the grain size and structure of the material. HIP also allows metal powder, polymer powder, ceramic powder and composite powder to be pressed into a solid form. The advantages include the fact that all the empty spaces inside metal components that are created through additional manufacturing methods are removed and that mechanical properties such as fatigue resistance / fatigue strength, toughness, plasticity and impact resistance are improved. Furthermore, HIP can create a dense material from metal powder, composite powder, polymer powder or ceramic powder without melting, and materials with partially different characteristics can be combined in the same component.

[0049] Using HIP, a solid material can be created from powder with superior properties because the powder / powder components have a fine, uniform grain size and an isotropic structure. Furthermore, with HIP, different metals can be joined together without needing a temperature-limiting adhesive. Using HIP, several diffusion bonds can be achieved in one process cycle. HIP works for a large number of metal alloys, such as polymers and ceramic material. For example, alloys with nickel, cobalt, tungsten, titanium, molybdenum, aluminum, copper and iron, oxide-and nitride ceramics, glass, intermetallic substances and polymers. HIP enables the bonding and combining of materials that otherwise cannot be combined, i.e. composites.

[0050] FIG. 1 shows a schematic sketch of the manufacture of a barrel segment 1 where a template core 20 is arranged in an outer tube 11, which is part of a capsule construction, so that a void, a cavity 30, is arranged between the capsule construction and the template core 20. In the cavity 30, powder can be arranged to manufacture a barrel segment 1 with HIP. barrel segment 1 can be made up of a complete barrel, but can also be made up of components for a complete barrel, then called a barrel segment. A complete barrel can thus be arranged by arranging several components, also called barrel segments, to complete a complete barrel.

[0051] FIG. 2a shows a view of a HIP container in the form of a capsule construction 10 for manufacturing a component for a barrel. The HIP container 10 is arranged with connection device 12, 14, for evacuating air, vacuum pumping, before and / or during the implementation of the manufacturing method, as well as a front bottom plate 16 and an outer tube 11.

[0052] FIG. 2b shows a cross-sectional view of a HIP container in the form of a capsule construction 10 for manufacturing a component for a barrel. The HIP container 10 is arranged with connection device 12, 14, for evacuation of air, vacuum pumping, before and / or during the implementation of the manufacturing method and a front bottom plate 16 and a rear bottom plate 18 and an outer tube 11. The powder is arranged freely in the HIP container in the form of the capsule assembly 10. between the capsule assembly 10 and a template core 20. Through continued HIP treatment, the powder can be fixed in the intended position in order to create a barrel segment 1. The material can be applied in powder form and shaken when they are located inside a HIP container in the form of capsule assembly 10, which is a surrounding component designed to hold powder, where powder, as the material to be applied, is arranged freely in the capsule assembly 10. Through continued HIP treatment, the powder can be fixed in the intended position in order to create a barrel segment 1. Manufacturing methods involving powder have advantages under cramped manufacturing conditions because the material supplied can reach into areas with small dimensions. Capsule assembly 10 is designed with a connecting device for evacuating air and vacuum pumping before and / or during the manufacturing process. Preferably, a first type of powder is provided in the capsule assembly 10 for the barrel other than the intermediate template core 20 and second type of powder is placed against the template core 20, which is not shown in the figure. The capsule assembly 10 is preferably made out of any material that a person skilled in the art considers suitable for the purpose. In one embodiment, the material in capsule assembly 10 is black sheet plate, and in another embodiment, the material is stainless steel, which also provides a rust-protection function for the barrel segment 1. The subcomponents of the capsule assembly can be manufactured additionally.

[0053] FIG. 3 shows a barrel 60 made of a number of barrel segments 1, 1′ arranged in a barrel casing 62. A complete barrel 60 includes additional barrel segments so that the entire barrel casing 62 is arranged with barrel segments. The first barrel segment 1 is arranged with chamber 2 and positioned where the barrel is arranged against the launch device and where the projectile is arranged for launch in the barrel 60. After the first barrel segment 1, subsequent barrel segments 1′, 1″ are arranged until the mouth of the barrel 4. Respective barrel segments 1, 1′, 1″ are manufactured based on the manufacturing method stated above and are arranged in a barrel casing 62 by heating the barrel casing 62 and thereby expanding to a state such that the barrel segments 1, 1′, 1″ can be arranged in the barrel casing 62. After the barrel segments 1, 1′, 1″ are arranged in the barrel casing 62, the barrel casing can cool so that the barrel casing contracts and barrel segments 1, 1′, 1″ are retained in the barrel casing 62 so that a complete barrel 60 is created. When a certain compressive stress is applied to the barrel segments 1, 1′, 1″ of the cooled barrel casing 62, autofrettage is achieved on the inner surface of the barrel, which results in improved resistance to crack propagation and / or crack formation.

[0054] FIG. 4 shows a template core 20 for manufacturing the first barrel segment 1. Template core 20 is arranged with a first part 21, for manufacturing chambers in barrel segment 1, and a second part 22 for manufacturing fluting in barrel segment 1. The template core is preferably made of metal but can also be made of other materials suitable for the continued method of manufacturing barrel segments.

[0055] FIG. 5 shows the manufacturing method 100 for barrel segment 1 with HIP. The outer tube 11, the rear bottom plate 18 and the front bottom plate 16 are arranged jointly in order to create a capsule assembly 10 in the step Designing a capsule assembly 102. A template core 20 is also arranged in the capsule assembly 10. A capsule assembly 10, also called a HIP container, is a device in which powder is arranged in a manner that allows it to be shaped into a HIPed body under high temperature and high pressure.

[0056] Powder in the capsule assembly 10 is arranged in the step Powder is arranged in the capsule assembly 104 by arranging powder between the template core 20 and outer tube 11. The template core 20 can be centered in the outer tube 11 by affixing the template core 20 to the rear bottom plate 18 and the front bottom plate 16.

[0057] After the powder material has been placed in the capsule assembly 10, the capsule assembly 10 is evacuated, vibrated and sealed in order to evenly distribute the powder in the capsule assembly 10 during the Evacuation, Vibration and Sealing step for capsule assembly 106. HIP is then carried out in the HIP 108 stage, i.e. a gas is used to create isostatic pressure on the capsule assembly 10 via a connecting device on the capsule assembly 60 that supplies the gas. Before the gas is supplied to the capsule assembly, the capsule assembly is vacuum-pumped or otherwise evacuated of air or the filling gas / fluid placed in the capsule assembly 10 prior to evacuation, e.g. by rinsing the assembly with a noble gas. Subsequently, the entire capsule assembly 10 is simultaneously heated to create a preform or a HIPed body. The HIP temperature is preferably 20% below the melting temperature for the material; for martensitic steel, the HIP temperature during the phase conversion (which is in the order of magnitude of 80% of the material's melting point). After the hot isostatic pressing is completed, the body can undergo heat treatment / hardening 110, which means that the now merged body is heated. After heat treatment, the material is suitable for processing, for example by means of machining entailing cutting, so that excess material, for example material covering the opening for the exit passage for gas flow and possibly parts of the HIP container is processed away in the step Machining / pickling 112 where machining entailing cutting such as lathe turning or milling but also pickling or other chemical treatment such as treatment with acid can be performed. The template core 20 is preferably removed by a combination of mechanical machining, such as lathe turning / drilling and pickling so that the riffling embedded in the barrel emerges. Where applicable, a surface treatment 114 is also performed.

[0058] Once barrel segment 1 is finalized, multiple barrel segments 1 may be assembled in order to create a barrel.

[0059] The material used for the powder is preferably factory steel or martensitic stainless steel with high concentrations of chromium and nickel, potentially with refractory material forming a layer on the muzzle brake in order to better withstand erosion from gun powder gases.

[0060] FIG. 6 shows manufacturing method 200 for manufacturing a barrel 60 from multiple barrel segments 1, 1′, 1″. Initially, barrel sheath 62, in which the barrel segments are arranged, is heated in the step Heating of barrel sheath 202. Once the barrel sheath 62 is heated, the barrel sheath 62 expands, which means that barrel segments 1, 1′, 1″ can be arranged in the barrel sheath 62. In the step barrel segments are arranged in barrel casing 204, one or more barrel segments 1, 1′, 1″ are arranged in barrel casing 62. In the step barrel segments including chambers are arranged in barrel casing 206, barrel segments with chamber 1 are arranged in the barrel casing to create a complete barrel 60. After the arrangement of barrel segments, the barrel can be cooled, which takes place in the step Cooling of barrel casing 208. When the barrel casing with barrel segments is cooled, a complete barrel 60 is completed, which can then be arranged in a firing device.

[0061] In an alternative embodiment regarding manufacturing method 200′ for barrel 60, only one barrel segment 1 is used Initially, the barrel sheath 62, in which the barrel segment 1 is arranged, is heated in the step Heating of barrel sheath 202. When the barrel casing 62 is heated, the barrel casing 62 expands, which means that the barrel segment 1 can be arranged in the barrel casing 62. In the step barrel segment is arranged in barrel casing 204, no barrel segment is arranged in the barrel casing 62 for the alternative embodiment of manufacturing method 200′ for barrels, instead arranged, in the step barrel segment comprising chambers are arranged in barrel casing 206, a barrel segment with chamber 1 in the barrel casing for the creation of a complete barrel 60. After the arrangement of barrel segments, the barrel can be cooled, which takes place in the step Cooling of barrel casing 208. When the barrel casing with barrel segments is cooled, a complete barrel 60 is completed, which can then be arranged in a firing device.

[0062] The invention is not limited to the embodiments specifically shown, but can be varied in different ways within the framework of the claims.

[0063] For instance, it is clear that the choice of material, choice of geometric forms, the elements and details included in the barrel or barrel components are adapted to the weapons system(s), platforms and other construction-related properties that are applicable at this time.

[0064] Furthermore, all types of barrels and barrel components, such as small caliber, medium caliber and large caliber barrels are included.

Examples

Embodiment Construction

[0039]The present invention shows embodiments of manufacturing methods for barrels and / or barrel components, such as barrel segments.

[0040]An ejection device, also termed a cannon, a howitzer, or a piece, in the sense of an artillery piece, has the goal of making use of a propellant for the purpose of firing a projectile. Preferably, a propellant, such as gunpowder, is initiated in one part of the cannon, oftentimes a chamber specifically adapted to the purpose. Initiation takes place by way of igniting the propellant, for instance by means of an ignition cartridge or an igniter in a munitions device, which is initiated by means of striking. Other methods for igniting the propellant may include ignition of the propellant by means of laser energy or electric energy. The propellant burns at a high rate and results in large amounts of gas being produced, which creates a gas pressure in the chamber which propels the projectile out of the barrel of the firing device. The propellant has b...

Claims

1. A method of manufacturing a barrel segment for a barrel, characterized by the method including the following steps:i.) arranging a capsule assembly so that it surrounds a template core (20), where the template core is fully or partially arranged with rifling for embossing rifling patterns on the barrel segment,ii.) arranging powder in the cavity between the capsule assembly and the template core,iii.) pressing the powder so that powder and capsule assembly are joined, andiv.) removing the template core in order to produce the barrel segment.

2. Method according to claim 1, characterized by the powder being pressed using high pressure and heat, also called Hot Isostatic Pressing, HIP.

3. Method according to claim 2, characterized by the barrel segment being heat-treated and hardened using Hot Isostatic Pressing when finishing a barrel segment4. Method according to claim 1, characterized by a metal film being arranged on the template core5. Method according to claim 4, characterized by the metal film being manufactured out of tantalum.

6. Method according to claim 1, characterized by the powder completely or partly consisting of tantalum.

7. Method according to claim 1, characterized by a pipe including tantalum being arranged on the template core.

8. Method for manufacturing a barrel, characterized by the method including the following steps:i.) heating up a barrel casingii.) arranging a first barrel segment including chambers, in the heated barrel casing andiii.) cooling the barrel consisting of the barrel casing arranged with barrel segments.

9. Method for manufacturing a barrel according to claim 8, characterized by the method further comprising the following steps:that at least a second barrel segment is arranged after the first barrel segment in the barrel casing prior to the barrel consisting of the barrel casing outfitted with barrel segments being cooled off.

10. A barrel manufactured according to claim 8.

11. A firing device designed with a barrel according to claim 10.

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