Barrel and method for manufacturing barrel and launching device including barrel

Abstract

The present invention relates to a method for manufacturing a barrel (1), wherein the method comprises the steps of: i.) providing a rifled barrel part (10) comprising a barrel provided with rifles, ii.) providing an extension part (20), iii.) providing a centring device (30) in the rifled barrel part (10) and the extension part (20) iv.) joining the extension part (20) to the rifled barrel part (10) to complete an extended barrel (1). Furthermore, the invention relates to a barrel, and a launching device comprising barrels.

Description

[0001] BARREL AND METHOD FOR MANUFACTURING BARREL AND LAUNCHING DEVICE INCLUDING BARREL

[0002] TECHNICAL FIELD

[0003] The present invention relates to a method for manufacturing a barrel, wherein the method comprises joining an extension piece to a grooved barrel piece to complete an extended barrel.

[0004] Furthermore, the invention relates to a barrel, and an launching device equipped with a barrel.

[0005] BACKGROUND OF THE INVENTION, PROBLEM STATEMENT AND KNOWN TECHNOLOGY

[0006] Gun barrel-based weapons are fired by burning gunpowder, thereby creating a gas expansion which propels a projectile in a barrel. Barrels equipped with rifling are preferably equipped with rifling with a pitch over the length of the barrel, which causes the projectile to rotate during the firing process. Rotation of the projectile is desirable in order to achieve a rotationally stabilised projectile, i.e. the projectile rotates after it has left the barrel. As an alternative to a rotationally stabilised projectile, the projectile can be stabilised with, for example, fins, in which case it may be desirable for the projectile not to rotate when it leaves the barrel, which is why the projectile in this case can be designed with a rotating or slipping driving band, which means that the projectile does not, or only to a certain extent, rotate during the launch phase of the projectile when the projectile is fired from a rifled barrel. When the projectile leaves the barrel in this case, it is stabilised by fins arranged on the projectile. Alternatively, the projectile can be fired from a barrel without rifling, also known as a smoothbore barrel, which means that no rotational force is transferred to the projectile during the launch process.

[0007] Conventionally, barrels are manufactured by lathing or cutting a forged blank. These manufacturing methods are limited by the size of the blank that can be producedusing the available manufacturing equipment, resulting in a barrel that is adapted to the manufacturing limitations of the current equipment and not to the functional requirements of the barrel.

[0008] Even if larger machines could be used, this could result in a relatively heavy barrel.

[0009] Conventional manufacturing and grooving of barrel involves several stages of cutting, including turning, drilling, grooving and honing with specially adapted equipment, which entails high costs for specially adapted manufacturing equipment, but also limited possibilities to change the length and other properties of the barrel.

[0010] An example of a manufacturing method for barrels is given in patent specification US H82, which describes a method for manufacturing a barrel in which different components of different materials and sizes are friction welded to complete the barrel.

[0011] The above-known technology does not disclose methods for manufacturing long artillery barrels.

[0012] Further problems that the present invention aims to solve are apparent in connection with the following detailed description of the various embodiments.PURPOSE AND CHARACTERISTICS OF THE INVENTION

[0013] The purpose of the present invention is to provide an improved method for manufacturing an extended barrel with the possibility of adapting the weight, length and rifling design based on the technical requirements of the barrel and not on manufacturing limitations.

[0014] The invention relates to a method for manufacturing a barrel, wherein the method comprises the steps of:

[0015] i.) providing a rifled barrel part comprising a passage or bore arranged with rifling, ii.) making an extension part,

[0016] iii.) providing a centring device in the rifled barrel part and the extension part, iv.) joining the extension part to the rifled barrel part to complete an extended barrel.

[0017] According to further aspects of the method for manufacturing a barrel according to the invention, the following applies:

[0018] t h e extension part is smooth-bore.

[0019] t h e joining of the extension part to the rifled barrel section is done by friction welding.

[0020] t h e extension part and / or the rifled barrel part are arranged with a gear ring that is used to rotate the extension part and / or the rifled barrel part during friction welding.

[0021] t h e gear ring, which has been used to rotate the extension part and / or the rifled barrel part during friction welding, is removed from the barrel by cutting after the friction welding has been completed.

[0022] t h e extension part is provided with wire winding.

[0023] t h a t when the extension part is joined to the rifled barrel part, the bore is honed.The invention further comprises a barrel.

[0024] According to further aspects of the barrel according to the invention, the following applies:

[0025] t h e calibre of the barrel is between 105 mm - 155 mm.

[0026] The invention further comprises an launching device including a barrel.

[0027] ADVANTAGES AND EFFECTS OF THE INVENTION

[0028] By manufacturing a barrel by arranging an extension on a conventional barrel, an improved long barrel can be manufactured with reduced weight, which results in improved barrel performance as the deformation of the barrel due to its own weight is reduced or completely avoided. Long barrels are important for achieving long firing distances for projectiles fired from the barrel, as both the amount of gunpowder and / or energy content are adjusted to create higher pressure on the projectile in the barrel, thereby resulting in a higher muzzle velocity for the projectile. Furthermore, the length of the barrel is important, as a long barrel allows a greater amount of the chemical energy in the gunpowder to be converted into kinetic energy in the projectile, as the time for the pressure to propel the projectile increases. Long barrels can be difficult to manufacture, as the manufacturing equipment for turning, drilling, rifling and honing barrels is often adapted to a specific barrel length, which can make it expensive and time-consuming to develop / produce new manufacturing equipment. If long barrels can be manufactured in a simpler way, for example by joining parts to form a shorter barrel, a long barrel can be manufactured at a lower cost. Barrels manufactured using conventional manufacturing methods also weigh more, which can cause the barrel to fail, especially since a muzzle brake is often installed at the muzzle of the barrel, which further increases the risk of the barrel failing. In the case of a long rifled barrel, wear on the driving band will increase during the firing process, which can lead to both wear on the barrel and gas leakage. It may therefore be advantageous to design parts of the barrel, preferably the part of the barrel closest to the muzzle, with a smooth bore in order to reduce both barrel wear and wear on the belt.LIST OF FIGURES

[0029] The invention will be described in more detail below with reference to the accompanying figures, where:

[0030] Fig. 1 shows a cross-sectional view of a barrel, according to one embodiment of the invention.

[0031] Fig. 2 shows a detailed cross-sectional view of a part of a barrel, according to one embodiment of the invention.

[0032] Fig. 3 shows the method steps for manufacturing a barrel, according to one embodiment of the invention.

[0033] DETAILED DESCRIPTION OF THE INVENTION

[0034] The present invention discloses embodiments of manufacturing methods for barrel, barrels, and launching devices comprising barrels.

[0035] A launching device or ejection device, also referred to as a cannon, howitzer, or gun, such as an artillery piece, is intended to fire a projectile using a propellant.

[0036] Preferably, a propellant, such as gunpowder, is initiated in a part of the cannon, often a chamber specially adapted for this purpose. Ignition occurs through the ignition of the propellant, for example with a primer or a detonator in an ammunition unit, which is initiated by impact. Other methods of igniting the propellant include laser or electrical energy. The propellant bums at high speed and generates a large amount of gas, which creates gas pressure in the chamber that drives the projectile out of the barrel of the firing device. The propellant is designed to generate as constant pressure as possible on the projectile throughout the entire barrel, as the projectile moves through the barrel, creating a high velocity for the projectile as it leaves the muzzle of the barrel.Projectiles, such as various types of grenades, in most cases include some form of warhead and some form of fuse or fuze that initiates the warhead. Fuses can be of various types, with impact fuses being common for projectiles that are intended to detonate on contact with an object, time fuses for projectiles that are intended to detonate at a predetermined time, and proximity fuses for projectiles that are intended to detonate when an object comes within a certain distance of the projectile. The warhead preferably comprises some form of explosive and some form of fragmentation casing that encloses the explosive. Furthermore, various forms of control devices, such as fins, can be arranged in the fuse or in a separate subcomponent.

[0037] In order to stabilise the projectiles after they have left the barrel, the projectiles are preferably designed with rotation or fins. In the case where the projectiles are designed with rotation, the projectiles are said to be rotationally stabilised, and in the case where the projectiles are designed with fins, the projectiles are said to be fin-stabilised. Fin-stabilised projectiles should not have rotation or low rotation when they leave the barrel.

[0038] To achieve rotation of the projectiles, rifling is preferably arranged in the barrel to which the projectile mechanically connects during the firing process. Rifling means that the barrel of a firearm, the barrel, is provided with spiral-shaped grooves. The opposite is a smoothbore barrel. When the grooves in the barrel engage with the projectile during firing, the projectile rotates along its longitudinal axis. The rotation prevents minor irregularities or damage to the projectile from causing a deviation in its trajectory. 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 rotationally stabilised. Only round (spherical) projectiles or fin-stabilised projectiles can be fired from smoothbore weapons. An elongated projectile without fins will tumble when it leaves the muzzle.

[0039] Rifling is thus grooves arranged in the barrel of the firearm, and the elevation between the grooves is called lands. Usually, the rifling in small-calibre handguns consists of four right-handed grooves, while cannons, such as artillery pieces, have alarger number of grooves depending on the calibre of the launching device. In order for the rifling to engage the projectile, the projectile must either be slightly larger than the diameter between the bores, which is common for small-calibre weapons, or be equipped with a special flange, called a driving band, which has a slightly larger diameter than the bores, which is common in projectiles with a diameter greater than 20 mm. The driving band can be made of plastic, composite material or a soft metal, such as copper or a copper alloy. The length of the barrel over which the rifling twists a full turn is called the pitch and is usually specified in inches per turn.

[0040] Most barrels include rifling, and by designing projectiles with slipping or rotating bands, both rotation-stabilised and fin-stabilised projectiles can be fired with rifled barrels. Smoothbore barrels are used almost exclusively for weapon systems designed to combat armoured combat vehicles, as the rotation of the projectile causes the shaped charge effect to be less effective because the centrifugal force causes the blast to spread out.

[0041] Long firing ranges are a capability that has been sought after in the development of barrel-based weapons. To achieve long firing ranges, the energetic material itself, which is initiated in the ejection device, and / or the ejection device itself can be adapted to achieve high velocities for the projectile as it leaves the barrel.

[0042] Furthermore, the projectile can be adapted to have as low air resistance as possible and be equipped with various technical solutions to increase the firing range, such as a base flow unit or rocket motor. With regard to the energetic material, preferably gunpowder, both the amount of gunpowder and / or its energy content can be adapted to create higher pressure on the projectile in the barrel and thus result in a higher initial velocity of the projectile. Furthermore, the length of the barrel is important, as a long barrel allows a greater amount of the chemical energy in the gunpowder to be converted into kinetic energy in the projectile, as the time for the pressure to propel the projectile increases. Manufacturing long barrels also presents some problems, for example, special equipment is required to turn, drill, groove and chamfer very long barrels. Furthermore, the weight of long barrels increases, which entails a risk of the barrel failing, especially since a muzzle brake is usually fitted at the muzzle of the barrel with increased weight at the muzzle of the barrel. Furthermore, a longer barrelincreases wear on the driving band of the projectile, as the driving band rests against the barrel for a longer period of time, which can lead to gas leakage.

[0043] An example of a historical cannon with a long barrel is the Paris Cannon, which had a 34-metre-long barrel comprising a smooth-bore extension fitted with a bolt joint on a conventional barrel fitted with a rifled liner. The barrel was fitted with a truss structure on the upper side of the barrel to reduce the risk of the barrel failing due to its own weight.

[0044] For artillery barrels, a common calibre is 155 mm. Barrel length has gone from a length of 39 calibres (6045 mm) to a length of 52 calibres (8060 mm), and trials are now underway with a 58-calibre barrel length, which corresponds to 8990 mm.

[0045] Fig. 1 shows a barrel 1 comprising a rifled barrel section 10, comprising a rifled barrel part 14 and a chamber 12, and an extension part 20. The rifled barrel section 10 and the extension part 20 have a bore in which the projectile is arranged to be fired. The part of the barrel, the rifled barrel section 10, which comprises the rifled barrel section 14 and the chamber 12, is preferably manufactured using conventional manufacturing methods with conventional machines and in conventional sizes. The extension part 20 is preferably arranged to the rifled barrel part 14, on the rifled barrel section 10, by friction welding. A centring device 30 is arranged in the common bore between the extension part 20 and the rifled barrel section 10.

[0046] Friction welding is a welding method in which two materials or components are joined or coordinated by friction. Friction welding utilises friction heat generated by rotating two components relative to each other. The friction causes the surfaces of the components to become hot enough to create a fusion between the two components so that the components are joined by melting the surface to a certain extent. It is possible to join components made of, for example, composite materials, metal or polymers. The friction welding method involves placing two components in a machine or other device for friction welding. Preferably, one component is arranged to rotate and one component is fixed in place. The rotating part is pressed or otherwise brought into contact with the fixed, stationary component with a specificpressure. The friction between the surfaces generates heat, which softens the surfaces without melting them completely. When sufficient heat and pressure are achieved, the material on the surfaces is plasticised and the material is joined. When the friction decreases, the surfaces are pressed together and create a strong weld joint.

[0047] There are several advantages to friction welding, for example, the material does not melt, which minimises the risk of pores or other defects that can occur during fusion welding. Friction welding produces very strong and durable j oints, which, combined with fewer pores, leads to high-quality welds. Furthermore, friction welding is an energy-efficient method as it does not require external heat sources such as a melting furnace, which also means that, as friction welding does not use melting or filler metal, it also results in lower emissions and less waste.

[0048] Friction welding is particularly useful for joining difficult-to-weld materials such as aluminium, copper and titanium. Friction welding is a fast, clean and precise welding method that enables strong and durable joints with minimal impact on the properties of the materials.

[0049] Fig. 2 shows a section of the barrel 1 relating to the rifled barrel section 14 on the rifled barrel part 10 and extension part 20. The rifled barrel section 14 ends with a mouth section 16 which is preferably not grooved, as is usually the case for mounting a muzzle brake when the rifled barrel part 10 is used as a free-standing barrel. An extension part 20 is arranged for the rifled barrel part 10 and preferably consists of a non-grooved tube with a thinner wall thickness relative to the rifled barrel part 10 in order to reduce the total weight of the barrel 1 and reduce the risk of the barrel buckling under its own weight. The extension part 20 can be provided with wire winding 22, for example a wire made of carbon fibre reinforced composite or glass fibre reinforced composite, which is wound onto the extension part and preferably fixed to the extension part 20. By wire winding the extension part, the extension part is prestressed. After the extension part 20 has been friction welded to the rifled barrel part 10, the thread 40 on the barrel 1 can be chamfered to ensure that the transition between the rifled barrel part 10 and the extension part is as smooth as possible.Furthermore, the extension part 20 and / or the rifled barrel part 10 can be fitted with a gear ring or other device to enable rotation of the rifled barrel part 10 relative to the extension part 20.

[0050] Fig. 3 shows a method for manufacturing long barrel 100, starting with the method step of Arranging a rifled barrel part 102 where a barrel is arranged, for example a barrel manufactured using conventional manufacturing technology as an existing barrel from an artillery system. As there are established manufacturing processes for artillery barrels, it is advantageous to utilise available resources to produce barrels using conventional manufacturing methods including turning, drilling, rifling and honing. The second method step, Arrangement of an extension part 104, involves arranging an extension part, which may consist of a tube with a smaller wall thickness relative to the rifled barrel part. The extension part is preferably not rifled. In the third step, Arrangement of centering device in the rifled barrel part and the extension part 106, a centring device is arranged j ointly for the rifled barrel part and the extension part. The centring device is preferably a rod, or other cylindrical object, with an outer diameter corresponding to or close to the inner diameter of the rifled barrel part and / or the extension part. In the fourth method step, Joining the extension part to the rifled barrel part 108, the extension part is joined to the rifled barrel part, for example by friction welding or another thermal joining technique such as other types of welding. The centring device acts as a jig or guide that ensures that the rifled barrel part and the extension part are arranged with a common centre line. When the rifled barrel part and the extension part are joined, the finished barrel can be machined, for example by honing, to ensure that the transition between the rifled barrel part and the extension part is such that projectiles are not affected, which is done in the step Honing of the joined barrel 110. Honing of the joined barrel 110 is not a necessary method step in the event that the method step Joining the extension part to the rifled barrel part 108 is performed with such a result that the joint between the rifled barrel part and the extension part is insignificant or non-existent.

[0051] Furthermore, the technical performance of the barrel can be improved by arranging the extension part with a reinforcement, for example by wire winding, which is done in the step Provide extension part with wire winding 112. The method step Provide extension part with wire winding 112 is not a mandatory method step; instead, theextension part can be manufactured or otherwise provided so that the extension part meets the requirements regarding strength, weight or other technical parameters required without being modified with wire winding.

[0052] ALTERNATIVE DESIGNS

[0053] The invention is not limited to the specifically shown embodiments, but may be varied in various ways within the scope of the patent claims.

[0054] It is understood, for example, that the choice of materials, the choice of geometric shapes, the elements and details included in the barrels or barrel components are adapted to the weapon system(s), platform and other design characteristics currently available.

[0055] Furthermore, all forms of barrel and barrel components for small calibre, medium calibre and large calibre are included.

Claims

PATENT CLAIMS1. Method for manufacturing a barrel (1), characterised in that the method comprises the steps of:1.) providing a rifled barrel part (10) comprising a rifled bore,ii.) providing an extension part (20),iii.) providing a centring device (30) in the rifled barrel part (10) and the extension part (20).iv.) joining the extension part (20) to the rifled barrel part (10) to complete an extended barrel (1).

2. Method for manufacturing a barrel (1) according to claim 1, characterised in that the extension part (20) is smooth-bore.

3. Method for manufacturing a barrel (1) according to any of requirements 1-2, characterised in that the extension part (20) is joined to the rifled barrel part (10) by friction welding.

4. Method for manufacturing a barrel (1) according to claim 3, characterised in that the extension part (20) and / or the rifled barrel part (10) are provided with a gear ring which is used to rotate the extension part (20) and / or the rifled barrel part (10) during friction welding.

5. Method for manufacturing a barrel (1) according to claim 4, characterised in that the gear ring used to rotate the extension part (20) and / or the rifled barrel part (10) during friction welding is removed from the barrel by cutting after the friction welding has been completed.6 Method for manufacturing barrel (1) according to any of requirements 1 - 5, characterised in that the extension part (20) is provided with wire winding (22).

7. Method for manufacturing a barrel (1) according to any of requirements 1-6, characterised in that when the extension part (20) is joined to the rifled barrel part (10), the bore is honed.

8. Barrel (1) manufactured according to any of requirements 1-7.

9. Barrel (1) according to claim 8, characterised in that the calibre of the barrel is 105 mm - 155 mm.

10. Launching device arranged with a barrel (1) according to any of requirements 8-9.

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