SE2300011A1 - Barrel - Google Patents

Abstract

The present invention relates to a method for producing fire tube segments (1), where the method includes the steps: i.) a capsule structure (10) is arranged surrounding a template core (20), ii.) powder is arranged in the cavity between the capsule structure (10) and the template core (20) ),iii.) the powder is pressed so that powder and capsule construction are joined, iv.) the template core (20) is removed for the production of a fire tube segment (1). The invention further relates to a method for manufacturing fire tubes, fire tubes and a launch device.

Description

'Received at the Patent and Registration Office 2023 -ÛZ~FIRE PIPE AND METHOD FOR MANUFACTURING FIRE PIPE SEGMENTS AND METHOD FOR MANUFACTURE OF FIRE PIPE AND LAUNCHING ARRANGEMENT INCLUDING FIRE PIPE TECHNICAL FIELD The present invention relates to a method for producing fire pipe segments comprising arranging a capsule structure surrounding a template core, and where powder is arranged in the cavity between the capsule construction and the template core and that the powder is pressed so that the powder and capsule construction are joined together and that the template core is removed for the production of a fire tube segment. Furthermore, the invention relates to a method for manufacturing fire tubes, fire tubes and ejection devices.

BACKGROUND OF THE INVENTION, PROBLEM STATEMENT AND PRIOR ART Barrel-based weapons are fired by burning gunpowder and thereby creating a gas expansion where the gas expansion moves a projectile in a barrel. Firing tubes arranged with a fluting are preferably arranged with a fluting with a rise above the spread of the firing tube, which means that the projectile is rotated during the firing process. Rotation of the projectile is desirable to provide a rotationally stabilized projectile, that is, the projectile rotates after the projectile exits the barrel. As an alternative to a rotationally stabilized projectile, the projectile can be stabilized with, for example, fins, in this case it may be desirable that the projectile does not rotate when the projectile leaves the barrel, which is why the projectile in this case can be arranged with a sliding girdle, which means that the projectile does not, or only to some extent, is rotated during the ejection phase of the projectile when the projectile is fired in a fluted fire tube. When the projectile in this case leaves the firing tube, the projectile is stabilized by fins arranged on the projectile. As an alternative, the projectile can be fired from a non-fluted fire tube, also known as smoothbore, which means that no rotational force is transferred to the projectile during the ejection procedure.

Conventionally, fire tubes are manufactured by cutting a cut material.

These manufacturing methods are partly costly and time-consuming and result in a Fire pipe that is adapted based on manufacturing technical limitations and not based on functional requirements for the fire pipe.

Conventional knurling of fire pipes includes several stages of cutting processing including drilling, turning, honing and knurling with equipment specially adapted for the purpose, which in part entails high costs but also limited opportunities to change the knurling's design.

An example of a manufacturing method for fluted fire tubes is given in patent document EP 0 339 692 A2, which describes a method for manufacturing a fire tube where an internal template is produced on which layers of refractory materials in the powder form are arranged.

The above prior art does not demonstrate that powder is arranged between the inner template and a capsule structure during manufacture.

Further problems that the present invention intends to solve appear in connection with the subsequent detailed description of the various embodiments.

Received at the Patent and Registration Office zuzs -nz- aa PURPOSE OF THE INVENTION AND ITS CHARACTERISTICS The purpose of the present invention is to achieve an improved way of manufacturing an improved fire pipe with the possibility of adapting the length and the design of the grooves based on the technical requirements of the fire pipe and not on the basis of manufacturing technical limitations .

The invention relates to a method for producing fire tube segments, where the method includes the steps: i.) a capsule structure is arranged surrounding a template core, ii.) powder is arranged in the cavity between the capsule structure and the template core, iii.) the powder is pressed so that powder and capsule structure are joined, iv. ) the template core (20) is removed to produce a fire tube segment (1).

According to further aspects for the method of producing fire pipe segments according to the invention apply; that the powder is pressed using high pressure and heat, also known as Hot Isostatic Pressing, HIP. that fire pipe segments are treated and hardened after Het lsostatic Pressing for the preparation of a fire pipe segment. a metal film is arranged on the template core. a t t the metal film is made of tantalum. powder wholly or partly composed of tantalum. a tube of tantalum is arranged on the template core. a t t the template core is fully or partially arranged with knurling for embossing knurled patterns on the fire tube segment. ' received at the Patent and Registration Office 2023 -ÛZ-The invention further consists of a method for manufacturing fire tubes characterized in that the method includes the steps; i.) a fire tube jacket is heated; ii.) a first fire tube segment, including chambers, is arranged in the heated fire tube jacket, iii.) fire tube consisting of a fire tube jacket arranged with fire tube segments is cooled.

According to further aspects for the method of producing fire tubes according to the invention apply; that at least one second fire tube segment is arranged after the first fire tube segment in the fire tube jacket before the fire tube consisting of a fire tube jacket arranged with fire tube segments is cooled.

The invention further consists of a fire pipe.

The invention further consists of a launch device including a fire tube.

BENEFITS AND EFFECTS OF THE INVENTION By manufacturing fire pipes or fire pipe components with a HIP, an improved fire pipe can be manufactured where the length of the fire pipe can be adapted based on the needs that exist instead of based on manufacturing technical limitations that currently limit fire pipe length. Furthermore, knurling of the fire tube can be carried out in a simpler way and with greater freedom to choose the design of the knurling compared to today's manufacturing methods for knurling fire tubes.

LIST OF FIGURES The invention will be described in more detail in the following with reference to the attached figures where: Reference to the Patent and Registration Office 2023 -ÛZ- ÛQ Fig. 1 shows a schematic view of the manufacture of fire tube segments, according to an embodiment of the invention.

Fig. 2a shows a capsule construction, according to an embodiment of the invention.

Fig. 2b shows a capsule construction in perspective, according to an embodiment of the invention. Fig. 3 shows a fire tube, according to an embodiment of the invention. Fig. 4 shows a template core, according to an embodiment of the invention.

Fig. 5 shows the process steps for Hot Isostatic Pressing, HIP, in the manufacture of a fire tube segment, according to an embodiment of the invention.

Fig. 6 shows the process steps in manufacturing a fire pipe from fire pipe segments, according to an embodiment of the invention.

DETAILED EMBODIMENT DESCRIPTION The present invention shows embodiments of manufacturing methods for fire pipes and/or components for fire pipes such as fire pipe segments.

A launching device, also called a cannon, howitzer, or piece, such as an artillery piece, is intended to release a projectile by means of a propellant. Preferably, a propellant, such as gunpowder, is initiated in a part of the cannon, often a chamber specially adapted for this. Initiation takes place by igniting the propellant, for example with an ignition cartridge or an igniter in an ammunition unit, which is initiated by impact. Other methods of igniting the propellant may be by laser or electrical energy igniting the propellant. The propellant burns at high speed and large gas development, which creates a gas pressure in the chamber that propels the projectile out of the fire tube of the launch device. The propellant is adapted to, to the greatest extent possible, generate a constant pressure on the projectile during the entire course of the firing tube, when the projectile moves in the firing tube, which creates a high velocity of the projectile when the projectile leaves the firing tube mouth.

Projectiles, such as different types of grenades, in most cases include some form of action part and some form of fuse that initiates the action part. Firing tubes can be of different types where impacts are common for projectiles that intend to detonate on contact with an object, time tubes when the projectile intends to detonate at a certain predetermined time and zone tubes when the projectile intends to detonate when an object comes within a certain distance of the projectile. Zone tubes are preferably used when combating aircraft and usually for medium caliber ammunition, for example 40 mm and 57 mm, while time tubes and targets can be used when combating a large number of different objects. Advantageously, different types of fuze function are combined in the same fuze, so that if a fuze with zone fuze function does not detect an object, the projectile breaks after a certain time, etc.

The action part preferably includes some form of explosive substance and some form of split casing that encloses the explosive substance. Furthermore, various forms of control means, such as fins, can be arranged either in the fuze or in a separate sub-component.

In order to stabilize the projectiles after the projectiles have left the fire tube, the projectiles are preferably arranged with rotation alternatively with fins. In the case that the projectiles are arranged with rotation, the projectiles are said to be rotationally stabilized and in the case that the projectiles are arranged with fins, the projectiles are said to be fin stabilized.

Fin-stabilized projectiles should have no rotation or low rotation as they leave the barrel.

In order to achieve rotation of the projectiles, grooves are often arranged in the fire tube to which the projectile connects during the firing process. Knurling means that the barrel of a firearm, the barrel, is provided with spiral grooves. The opposite is smooth bore fire pipe. When the rib floam engages the proj ectile during the firing, the proj ectile undergoes a rotation along its longitudinal axis. Through the rotation, minor debris or damage to the projectile will not cause a drift in the projectile's trajectory. Rotation is also necessary for an oblong (torpedo-shaped) projectile to maintain its direction after it leaves the course and not start tumbling around, this is called the projectile being lncome to the Patent and Registration Office 2023 -UZ rotation stabilized. In smoothbore weapons, only round (spherical) projectiles or fin-stabilized projectiles can be fired. An elongated projectile without fins will tumble as it leaves the muzzle.

Grooves are thus grooves arranged in the barrel of the fire tube, and the elevation between them is called booms. Typically, the rifling of fine-caliber firearms consists of four right-handed rifling, while cannons, such as artillery pieces, have a greater number of rifling depending on the caliber of the launcher. In order for the rifling to be able to engage the projectile, the projectile must either be slightly larger than the diameter between the booms, which is common for fincaliber weapons, or be fitted with a special flange, called a girdle, which has a slightly larger diameter than the booms, which is common occurring in projectiles with a diameter greater than 20 mm. The girdle can be made of plastic, composite material or a soft metal, such as copper or a copper alloy. The length of the barrel on which the flute turns one full revolution is called pitch and is usually given in inches per revolution. Most barrels include flutes and by arranging projectiles with sliding belts, both rotationally stabilized and fin-stabilized projectiles can be fired with rifled barrels. Smooth bore fire tubes are in principle only used for weapon systems intended to fight armored combat vehicles as the rotation of the projectile means that the directed blast effect, RSV, works worse because the centrifugal force causes the beam to spread out.

In the embodiment that includes fire tubes or components for fire tubes being manufactured with HIP, materials with high resistance to abrasion and thermal erosion gases, which arise when projectiles are fired from a fire tube, can 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 optimally used 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 component with high strength. Components manufactured with HIP Cladding have an improved lifetime and performance compared to components manufactured with the substrate alloy. Manufacturing of fire tube components/fire tube segments/fire tubes with HIP Cladding involves limited machining and/or surface treatment measures and a reduced number of process steps and thus shortens the lead time compared to forged and coated components. HIP Cladding means that selected surfaces can 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.

Hot isostatic pressing, HIP (in English Hot Isostatic Pressing), is a manufacturing process to control the grain size and structure of the material. HIP also enables the packing of metal, polymer, ceramic and composite powders into solid formers. The advantages include that all internal voids in metal components created by additive manufacturing methods are removed and that mechanical properties, such as fatigue resistance/wetting strength, toughness, plasticity and impact resistance, are improved. Furthermore, HIP can create a dense material from metal, composite, polymer or ceramic powder without melting and that materials with partly different characteristics can be coordinated in the same component.

With HIP, a solid material with superior properties can be created from powder as the powder/powder components have a fine, uniform particle size and isotropic structure. Furthermore, through the use of HIP, dissimilar metals can be joined without the need for temperature-limiting binders. Through HIP, several diffusion bonds can be achieved in a single process cycle. HIP works for a large number of metal alloys, as well as for example polymers and ceramic materials. For example, alloys with nickel, cobalt, tungsten, titanium, molybdenum, aluminium, copper and iron, oxide and nitride ceramics, glass, intermetallic substances and polymers. HIP enables bonding and combinations of materials that cannot otherwise be combined, i.e. composites. Entered the Patent and Registration Office 2023 -ÛZ~I flg. 1 shows a schematic sketch of the manufacture of a fire tube 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 arranged to manufacture a fire tube segment 1 with HIP. Fire pipe segment 1 can be made up of a complete fire pipe, but can also be made up of components for a complete fire pipe, then called a fire pipe segment. A complete fire pipe can thus be arranged by arranging several components, also called fire pipe segments, to complete a complete fire pipe.

In frg. 2a shows a view of a HIP container in the form of a capsule structure 10 for the manufacture of a component for a fire tube. I-IIP-containem 1-O 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 and an outer tube 1 in fig. 2b shows a cross-sectional view of an I-HP container in the form of a capsule construction 10 for the manufacture of a component for a fire tube. 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 freely arranged in the HIP container in shape of the capsule structure 10 between the capsule structure 10 and a template core 20. By further processing in accordance with HIP the powder is fixed in the intended place for the production of a fire tube segment 1. The material is applied in the powder former and is shaken in place inside a HIP container in the form of capsule construction 10, which is an enclosing component arranged to retain powder, where powder, in the form of applied material, is freely arranged in the capsule construction 10. Through further processing in accordance with HIP, the powder is fixed in the intended place for the production of a fire tube segment 1. Manufacturing methods including powder have advantages in cramped manufacturing conditions when the material supplied must reach into spaces with small dimensions. The capsule construction 10 is arranged with a connecting device for evacuation of air and vacuum pumping, before and/or during the implementation of the manufacturing method. Preferably, a first type of powder is arranged in the capsule construction 10 for the fire tube segment in addition to the nearby template core Submitted to the Patent and Registration Office zozs -uz- and a second type of powder is arranged against the template core 20 which is not shown in the figure. The capsule construction 10 is preferably made of any material that the skilled person realizes is suitable for the purpose. In one embodiment, the material in the capsule construction 10 is black sheet, in another embodiment, the material is stainless steel, which also contributes to a rust-protective function for the fire tube segment. The sub-components for the capsule construction can also be manufactured additively.

In flg. 3 shows a fire pipe 60 made of a number of fire pipe segments 1, 1' arranged in a fire pipe jacket 62. A complete fire pipe 60 includes additional fire pipe segments so that the entire fire pipe jacket 62 is arranged with fire pipe segments. The first firing tube segment 1 is arranged with chamber 2 and positioned where the firing tube is arranged against the launch device and where the projectile is arranged for ejection in the firing tube 60. After the first firing tube segment 1, subsequent firing tube segments 1', 1" are arranged up to the mouth of the firing tube 4. Respective firing tube segment 1, 1', 1" are manufactured based on the manufacturing method stated above and is arranged in a fire tube jacket 62 by heating the fire tube jacket 62 and thus expanding to a state so that the fire tube segments 1, 1', 1" can be arranged in the fire tube jacket 62. After the fire tube segments 1, 1', 1" are arranged in the fire tube jacket 62, the fire tube jacket can cool so that the fire tube jacket contracts and that fire tube segments l, 1 ', 1" is retained in the fire tube jacket 62 so that a complete fire tube 60 is created. When a certain compressive stress is applied to the fire tube segments 1, 1', 1" of the cooled fire tube jacket 62, autofrettage is achieved on the inner surface of the fire tube, which results in improved resistance to crack propagation and/or crack formation.

Fig. 4 shows a template core 20 for the manufacture of the first fire tube segment 1. The template core 20 is arranged with a first part 21, for the manufacture of chambers in the fire tube segment 1, and a second part 22 for the manufacture of grooves in the fire tube segment 1. The template core is preferably manufactured from metal but can also be made from other materials suitable for the continued method of manufacturing fire tube segments.

Fig. 5 shows manufacturing method 100 for fire tube segment 1 with HIP. Outer tube 11, the rear bottom plate 18 and the front bottom plate 16 are arranged together for the creation of a capsule structure 10 in the step Designing a capsule structure 102. In the capsule structure 10, a template core 20 is also arranged. One income iir; Para-n- and 'eSNSlïeringsverket 2023 -ÛZ-ll capsule construction 10, also called HIP container, is a device where powder is arranged to, under high temperature and high pressure, transform the powder into a HIPPAD body. Powder in the capsule structure 10 is arranged in the step Powder is arranged in the capsule structure 104 by arranging powder between the template core 20 and outer tube 1 1. The template core 20 can be centered in the outer tube 1 1 by aligning the template core to the rear bottom plate 18 and the front bottom plate After powder material is arranged in the capsule construction 10, the capsule structure 10 is evacuated, vibrated and sealed to dispense the powder evenly in the capsule construction 10 in the step Evacuation, vibration and closure of the capsule construction 106. Hot isostatic pressing is then carried out in the step HIP 108, that is, a gas is used to create an isostatic pressure on the capsule construction 10 by arranging the gas into a, on the capsule structure 60 arranged, connection device. Before the gas is arranged in the capsule structure, the capsule structure can be vacuum-pumped or otherwise evacuated using air or the filling gas/fluid which is arranged in the capsule structure 10 before evacuation, for example by flushing with a noble gas. Next, the entire capsule structure 10 is heated to create a preform or H1PPAD body. HIP temperature is preferably 20% below the melting temperature of the material, for martensitic stainless steels the HIP temperature is above the phase transformation to the austenitic state (which is on the order of 80% of the material's melting point). After hot isostatic pressing has been carried out, the body can undergo heat treatment/hardening 1 10, which means that the now joined body is heated. After heat treatment, the material is suitable for processing, for example cutting processing, 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 Processing/pickling 112 where cutting processing such as turning or milling but also pickling or other chemical treatment such as treatment with acid can be carried out. The template core 20 is preferably removed by a combination of mechanical processing, such as turning/drilling and pickling so that the knurling made in the fire tube segment will appear. If applicable, a surface treatment is also carried out 1 After the fire pipe segment 1 has been completed, several fire pipe segments 1 can be arranged to create a fire pipe.

Received at the Patent and Registration Office 2023 -IBZ- US Materials used as powder are preferably tool steel or martensitic stainless steel with high concentrations of chromium and nickel possibly with refractory material arranged in the surface of the muzzle brake to better resist erosion from gunpowder gases.

Fig. 6 shows manufacturing method 200 for manufacturing fire pipe 60 from several fire pipe segments l, l', l Initially, fire pipe jacket 62, in which the fire pipe segments are arranged, is heated in the step Heating of fire pipe jacket 202. When the fire pipe jacket 62 is heated, the fire pipe jacket 62 expands, which means that fire pipe segment l, l', l" can be arranged in fire pipe jacket 62. In the step Fire pipe segments are arranged in fire pipe jacket 204, one or more fire pipe segments l, l', l" are arranged in the fire pipe jacket 62. In the step Fire pipe segments including chambers are arranged in fire pipe jacket 206, fire pipe segments with chamber 1 are arranged in the fire pipe jacket for the creation of a complete fire pipe 60. After the arrangement of fire pipe segments, the fire pipe can is cooled, which takes place in the step Cooling of fire tube jacket 208. When the fire tube jacket with fire tube segments is cooled, a complete fire tube 60 is completed, which can continue to be arranged in an extension device.

In an alternative embodiment regarding manufacturing method 200' for fire pipe 60, only one fire pipe segment 1 is used. Initially, the fire pipe jacket 62, in which the fire pipe segment l is arranged, is heated in the step Heating of fire pipe jacket 202. When the fire pipe jacket 62 is heated, the fire pipe jacket 62 expands, which means that the fire pipe segment l can be arranged in the fire pipe jacket 62. In the step Fire pipe segment is arranged in fire pipe jacket 204, no fire pipe segment is arranged in the fire tube jacket 62 for the alternative execution liner form of manufacturing method 200 'for fire tubes, is instead arranged, in the step Fire tube segments comprising chambers are arranged in fire tube jacket 206, a fire tube segment with chamber 1 in the fire tube jacket for the creation of a complete fire tube 60. After the arrangement of fire tube segments, the fire tube can be cooled, which takes place in the step Cooling of the fire tube jacket 208. Then the fire tube jacket with fire tube segment is cooled, then a complete fire tube 60 is completed, which can then be arranged in an ejection device. received at the Patent and Registration Office 2023 -UZ- USALTERNATIVE EMBODIMENTS The invention is not limited to the specifically shown embodiments but can be varied in various ways within the framework of the patent claims.

It is understood, for example, that the choice of materials, the choice of geometric forms, the elements and details included in the fire tube or the fire tube components are adapted to the weapon system(s), platform and other construction characteristics that are available at the moment.

Furthermore, all forms of fire tubes and fire tube components are included for both fine caliber, medium caliber and coarse caliber.

Claims (11)

1. Method for the production of fire pipe segments (1), characterized in that the method includes the steps: i.) a capsule construction (10) is arranged surrounding a template core (20) where the template core (20) is fully or partially arranged with grooves for embossing groove patterns on the firing tube segment (1), ii.) powder is placed in the cavity between the canister structure (10) and the template core (20), iii.) the powder is pressed so that the powder and canister structure are joined together, iv.) the template core (20) is removed for the production of a firing tube segment (1 ). 2. Method according to claim 1, characterized in that the powder is pressed using high pressure and heat, also called Hot Isostatic Pressing, HIP. 3. Method according to claim 2, characterized in that fire pipe segments (1) are heat treated and hardened after Hot Isostatic Pressing for the completion of a fire pipe segment (1). 4. Method according to one of the above claims, characterized in that a metal film is arranged on the template core (20). 5. Method according to claim 4, characterized in that the metal film is made of tantalum. 6. Method according to one of claims 1 - 3, characterized in that the powder consists wholly or partly of tantalum. 7. Method according to one of claims 1 - 3, characterized in that a tube of tantalum is arranged on the template core (20). 8. Method for manufacturing fire tubes characterized in that the method comprises the steps; i.) a fire tube jacket (62) is heated; ii.) a first fire tube segment (1), including chambers, is arranged in the heated fire tube jacket (62), iii.) fire tube (60) consisting of a fire tube jacket (62) arranged with fire tube segments is cooled. 9. Method for manufacturing fire tubes according to claim 8, characterized in that the method further comprises the step of; at least one second fire pipe segment (1') is arranged after the first fire pipe segment (1) in the fire pipe jacket (62) before the fire pipe (60) consisting of a fire pipe jacket (62) arranged with fire pipe segments is cooled. 10. Fire pipe (60) manufactured according to any of claims 8 - 11. Ejection device arranged with fire tube according to claim 10.